Cimetidine interactions

• CYP3A Inhibitors: Avoid co-administration with strong CYP3A inhibitors. (Acalabrutinib label, Drug interactions)

Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex. (Acetaminophen and codeine label, Boxed warning)

…(Childs-Pugh categories B and C), since alfuzosin blood levels are increased in these patients [see Use in Specific Populations (8.7) and Clinical Pharmacology (12.3) ]. with potent CYP3A4 inhibitors such as ketoconazole, itraconazole, and ritonavir, since alfuzosin blood levels are increased [see Drug Interactions (7.1) and Clinical Pharmacology (12.3) ] . in… (Alfuzosin label, Contraindications)

Concomitant use of almotriptan tablets and potent CYP3A4 inhibitors should be avoided in patients with renal or hepatic impairment [see Clinical Pharmacology ( 12.3 )] . (Almotriptan label, Drug interactions)

Fluvoxamine, a known strong inhibitor of CYP1A2, has been shown to increase mean alosetron plasma concentrations (AUC) approximately 6-fold and prolong the half-life by approximately 3-fold [see Drug Interactions ( 7.1 )] . (Alosetron label, Contraindications)

• taking strong cytochrome P450 3A (CYP3A) inhibitors (e.g., ketoconazole, itraconazole), except ritonavir [see Dosage and Administration (2.5) , Warnings and Precautions (5.5) , Drug Interactions (7.1) ] . (Alprazolam label, Contraindications)

If concomitant use of DYANAVEL XR with other serotonergic drugs or CYP2D6 inhibitors is clinically warranted, initiate DYANAVEL XR with lower doses, monitor patients for the emergence of serotonin syndrome during drug initiation or titration, and inform patients of the increased risk for serotonin syndrome. (Amphetamine label, Warnings and precautions)

If serotonin syndrome occurs, discontinue ADDERALL XR and the CYP2D6 inhibitor [see Warnings and Precautions ( 5.8 ), Overdosage ( 10 )] . (Amphetamine and dextroamphetamine label, Drug interactions)

For patients receiving ELIQUIS at a dose of 2.5 mg twice daily, avoid coadministration with combined P-gp and strong CYP3A4 inhibitors [see Dosage and Administration (2.6) and Clinical Pharmacology (12.3) ] . (Apixaban label, Drug interactions)

Do not use avanafil in patients taking strong CYP3A4 inhibitors [see Warnings and Precautions ( 5.2 ) and Dosage and Administration ( 2.3 )]. (Avanafil label, Drug interactions)

Concomitant administration of BIXLENVO with combined P-gp, UGT1A1, and strong CYP3A inhibitors is not recommended. (Bictegravir, emtricitabine, and tenofovir alafenamide label, Drug interactions)

Co-administration of such combinations of a CYP2C9 inhibitor plus a strong or moderate CYP3A inhibitor with TRACLEER is not recommended. (Bosentan label, Drug interactions)

• Strong and Moderate CYP3A Inhibitors: Avoid concomitant use with BOSULIF. (Bosutinib label, Drug interactions)

Concomitant use of strong CYP3A4 inhibitors (e.g., azole antimycotics, HIV protease inhibitors) with CYCLOSET should be avoided. (Bromocriptine label, Drug interactions)

Evaluate patients starting CYP3A4 inhibitors or stopping CYP3A4 inducers at frequent intervals for respiratory depression. (Buprenorphine label, Drug interactions)

Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex. (Butalbital, acetaminophen, caffeine, and codeine label, Boxed warning)

The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex. (Butalbital, aspirin, caffeine, and codeine label, Boxed warning)

Avoid taking a strong CYP3A4 inhibitor (e.g., ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, voriconazole) while taking COMETRIQ or reduce the dosage of COMETRIQ if concomitant use with strong CYP3A4 inhibitors cannot be avoided [see Dosage and Administration ( 2.2 ), Clinical Pharmacology… (Cabozantinib label, Drug interactions)

Concomitant use of cimetidine should be avoided. (Chloroquine label, Drug interactions)

Avoid use of Citalopram Capsules in CYP2C19 poor metabolizers, patients receiving concomitant cimetidine or another CYP2C19 inhibitor, patients with hepatic impairment, and patients who are greater than 60 years of age, because Citalopram Capsules are only available in a 30 mg dose strength and dosage adjustments are not possible [see Drug Interactions ( 7 ),… (Citalopram label, Warnings and precautions)

CYP2C19 inhibitors: Avoid concomitant use of omeprazole or esomeprazole. (Clopidogrel label, Warnings and precautions)

Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex. (Codeine label, Boxed warning)

Patients with renal or hepatic impairment should not be given colchicine capsules with drugs that inhibit both P-glycoprotein and CYP3A4 inhibitors [see Drug Interactions (7) ] . (Colchicine label, Contraindications)

Strong CYP3A4 inhibitors: Avoid concomitant use. (Daridorexant label, Drug interactions)

Avoid concomitant use of strong CYP3A4 inhibitors. (Dasatinib label, Drug interactions)

• Avoid concomitant use of strong CYP3A4 inhibitors or inducers. (Dexamethasone label, Drug interactions)

If serotonin syndrome occurs, discontinue dextroamphetamine sulfate and the CYP2D6 inhibitor [see Warnings , Overdosage ]. (Dextroamphetamine label, Drug interactions)

QT Prolongation: Monitor ECG if concomitant use of drugs that prolong QT interval cannot be avoided or if concomitant CYP3A4 inhibitors used. (Dextromethorphan and quinidine label, Warnings and precautions)

WARNING: PERIPHERAL ISCHEMIA FOLLOWING COADMINISTRATION WITH POTENT CYP3A4 INHIBITORS Serious and/or life-threatening peripheral ischemia has been associated with the coadministration of dihydroergotamine with potent CYP3A4 inhibitors including protease inhibitors and macrolide antibiotics. (Dihydroergotamine label, Boxed warning)

Concomitant use of Docetaxel Injection and drugs that inhibit CYP3A4 may increase exposure to docetaxel and should be avoided. (Docetaxel label, Drug interactions)

The concomitant use of verapamil or the cation transport system inhibitors cimetidine, trimethoprim (alone or in combination with sulfamethoxazole), or ketoconazole with dofetilide is contraindicated (see WARNINGS and PRECAUTIONS, Drug-Drug Interactions ), as each of these drugs cause a substantial increase in dofetilide plasma concentrations. (Dofetilide label, Contraindications)

Avoid concomitant use of Doxorubicin Hydrochloride Injection with inhibitors of CYP3A4, CYP2D6, or P-gp. (Doxorubicin label, Drug interactions)

Strong CYP1A2 inhibitors : Avoid concomitant use. (Duloxetine label, Drug interactions)

Drug-Drug Interactions Strong Inhibitors of Cytochrome P450 (CYP) 3A4 Tamsulosin-containing products, including JALYN, should not be coadministered with strong CYP3A4 inhibitors (e.g., ketoconazole) as this can significantly increase tamsulosin exposure [see Drug Interactions (7.1) , Clinical Pharmacology (12.3) ]. (Dutasteride and tamsulosin label, Warnings and precautions)

• Recent use (i.e., within at least 72 hours) of the following potent CYP3A4 inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, or nelfinavir [see Drug Interactions (7.2) and Clinical Pharmacology (12.3) ]. (Eletriptan label, Contraindications)

Use of RPV with proton pump inhibitors is contraindicated and use of RPV with H 2 -receptor antagonists requires staggered administration [see Contraindications (4) and Clinical Pharmacology (12.3) ] . (Emtricitabine, rilpivirine, and tenofovir label, Drug interactions)

…Patients Eplerenone is contraindicated in all patients with: • serum potassium > 5.5 mEq/L at initiation, • creatinine clearance ≤ 30 mL/min, or • concomitant administration of strong CYP3A inhibitors (e.g., ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, and nelfinavir) [see Drug Interactions (7.1) , Clinical Pharmacology (12.3)… (Eplerenone label, Contraindications)

WARNING Serious and/or life-threatening peripheral ischemia has been associated with the coadministration of ergotamine tartrate and caffeine tablets with potent CYP 3A4 inhibitors including protease inhibitors and macrolide antibiotics. (Ergotamine and caffeine label, Boxed warning)

Avoid co-administering erlotinib with strong CYP3A4 inhibitors (e.g., boceprevir, clarithromycin, conivaptan, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telithromycin, voriconazole, grapefruit or grapefruit juice) or a combined CYP3A4 and CYP1A2 inhibitor (e.g., ciprofloxacin). (Erlotinib label, Drug interactions)

Consequently, estazolam should be avoided in patients receiving ketoconazole and itraconazole, which are very potent inhibitors of CYP3A (see CONTRAINDICATIONS ). (Estazolam label, Warnings)

VYTORIN is contraindicated in the following conditions: Concomitant use of strong CYP3A4 inhibitors (select azole anti-fungals, macrolide antibiotics, anti-viral medications, and nefazodone) [see Drug Interactions (7.1) ] . (Ezetimibe and simvastatin label, Contraindications)

Famotidine Injection is contraindicated in patients with a history of serious hypersensitivity reactions (e.g., anaphylaxis) to famotidine or other H 2 -receptor antagonists. (Famotidine label, Contraindications)

• Concomitant use with CYP3A4 inhibitors (or discontinuation of CYP3A4 inducers) can result in a fatal overdose of fentanyl. (Fentanyl label, Boxed warning)

CYP3A4 Inhibitors Doses of Toviaz greater than 4 mg are not recommended in adult patients taking strong CYP3A4 inhibitors, such as ketoconazole, itraconazole, and clarithromycin [see Dosage and Administration (2.5) ]. (Fesoterodine label, Drug interactions)

Contraindicated with Strong or Moderate CYP3A4 Inhibitors The concomitant use of ADDYI and moderate or strong CYP3A4 inhibitors increases flibanserin concentrations, which can cause severe hypotension and syncope [see Warnings and Precautions (5.2) ] . (Flibanserin label, Boxed warning)

Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir, ketoconazole): Use not recommended. (Fluticasone label, Drug interactions)

Avoid strong cytochrome P450 3A4 inhibitors (e.g., ritonavir, ketoconazole): May increase risk of systemic corticosteroid and cardiovascular effects. (Fluticasone and salmeterol label, Drug interactions)

Cytochrome P450 3A4 Interaction The concomitant use of HYSINGLA ER with all cytochrome P450 3A4 inhibitors may result in an increase in hydrocodone plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. (Hydrocodone label, Boxed warning)

Cytochrome P450 3A4 Interaction The concomitant use of hydrocodone bitartrate and acetaminophen tablets with all Cytochrome P450 3A4 inhibitors may result in an increase in hydrocodone plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. (Hydrocodone and acetaminophen label, Boxed warning)

Cytochrome P450 3A4 Interaction The concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex with all cytochrome P450 3A4 inhibitors may result in an increase in hydrocodone plasma concentrations, which could increase or prolong adverse drug effects and may cause potentially fatal respiratory depression. (Hydrocodone and chlorpheniramine label, Boxed warning)

Cytochrome P450 3A4 Interaction The concomitant use of hydrocodone bitartrate and homatropine methylbromide with all cytochrome P450 3A4 inhibitors may result in an increase in hydrocodone plasma concentrations, which could increase or prolong adverse drug effects and may cause potentially fatal respiratory depression. (Hydrocodone and homatropine label, Boxed warning)

Cytochrome P450 3A4 Interaction The concomitant use of Hydrocodone Bitartrate and Ibuprofen Tablets with all cytochrome P450 3A4 inhibitors may result in an increase in hydrocodone plasma concentrations, which may cause potentially fatal respiratory depression. (Hydrocodone and ibuprofen label, Boxed warning)

Avoid concomitant use of cimetidine 7.9 Rifampicin Lack of efficacy of hydroxychloroquine was reported when rifampicin was concomitantly administered. (Hydroxychloroquine label, Drug interactions)

Ibuprofen and famotidine tablet should not be administered to patients with a history of hypersensitivity to other H 2 -receptor antagonists. (Ibuprofen and famotidine label, Contraindications)

• Strong CYP3A4 Inhibitors: Do not administer strong CYP3A4 inhibitors with CAMPTOSAR. (Irinotecan label, Drug interactions)

Co-administration with eliglustat is contraindicated in poor or intermediate metabolizers of CYP2D6 and in subjects taking strong or moderate CYP2D6 inhibitors. (Itraconazole label, Boxed warning)

…bradycardia [see Warnings and Precautions ( 5.3 )] • Severe hepatic impairment [see Use in Specific Populations ( 8.6 )] • Pacemaker dependence (heart rate maintained exclusively by the pacemaker) [see Drug Interactions ( 7.3 )] • Concomitant use of strong cytochrome P450 3A4 (CYP3A4) inhibitors [see Drug Interactions ( 7.1 )] Acute decompensated heart failure ( 4 ) (Ivabradine label, Contraindications)

Avoid strong CYP3A4 inhibitors. (Lapatinib label, Drug interactions)

Strong CYP3A4 Inhibitors: Avoid coadministration of strong CYP3A4 inhibitors with VITRAKVI. (Larotrectinib label, Drug interactions)

Strong or moderate CYP3A inhibitors: Avoid concomitant use. (Lemborexant label, Drug interactions)

If concomitant use of VYVANSE with other serotonergic drugs or CYP2D6 inhibitors is clinically warranted, initiate VYVANSE with lower doses, monitor patients for the emergence of serotonin syndrome during drug initiation or titration, and inform patients of the increased risk for serotonin syndrome. (Lisdexamfetamine label, Warnings and precautions)

Concomitant administration of JUXTAPID with moderate or strong CYP3A4 inhibitors, as this can increase JUXTAPID exposure [see Warnings and Precautions (5.6) , Drug Interactions (7.1) , and Clinical Pharmacology (12.3) ]. (Lomitapide label, Contraindications)

• Strong CYP3A Inhibitors : Avoid concomitant use; reduce LORBRENA dose if concomitant use cannot be avoided. (Lorlatinib label, Drug interactions)

Concomitant administration with strong CYP3A4 inhibitors (e.g., itraconazole, ketoconazole, posaconazole, voriconazole, HIV protease inhibitors, boceprevir, telaprevir, erythromycin, clarithromycin, telithromycin, nefazodone and cobicistat-containing products) (see WARNINGS , Myopathy/Rhabdomyolysis ). (Lovastatin label, Contraindications)

Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin, ritonavir, voriconazole, mibefradil, etc.) [see Drug Interactions ( 7.1 )]. (Lurasidone label, Contraindications)

Strong CYP3A4 inhibitors (ketoconazole, ritonavir) increase exposure to macitentan: avoid co-administration with OPSUMIT ( 7.2 , 12.3 ) . (Macitentan label, Drug interactions)

SELZENTRY is contraindicated in patients with severe renal impairment or ESRD (creatinine clearance [CrCl] less than 30 mL per minute) who are concomitantly taking potent CYP3A inhibitors or inducers [see Warnings and Precautions ( 5.3 )]. (Maraviroc label, Contraindications)

Cimetidine Clinical Impact: The concomitant use of cimetidine may reduce the clearance and volume of distribution of meperidine also the formation of the metabolite, normeperidine, in healthy subjects Intervention: If concomitant use cimetidine and DEMEROL Injection is necessary, monitor patients for respiratory depression and sedation at frequent intervals. (Meperidine label, Drug interactions)

Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The concomitant use of METHADOSE with all cytochrome P450 3A4, 2B6, 2C19, 2C9 or 2D6 inhibitors may result in an increase in methadone plasma concentrations, which could cause potentially fatal respiratory depression. (Methadone label, Boxed warning)

If serotonin syndrome occurs, discontinue methamphetamine hydrochloride tablets, USP and the CYP2D6 inhibitor [see Warnings and Precautions 5.8]. (Methamphetamine label, Drug interactions)

Although there have been no reports of such interactions with methylergonovine alone, strong and moderate CYP 3A4 inhibitors should not be co-administered with methylergonovine. (Methylergonovine label, Drug interactions)

Intervention Concomitant use of methylphenidate extended-release orally disintegrating tablets with a gastric pH modulator (i.e., a H2-blocker or a proton pump inhibitor) is not recommended. (Methylphenidate label, Drug interactions)

CYP2D6 Inhibitors Monitor patients closely when the combination use of CYP2D6 inhibitor and metoprolol cannot be avoided. (Metoprolol label, Drug interactions)

Strong CYP3A Inhibitors and Inducers: Avoid concomitant use. (Mitapivat label, Drug interactions)

Patients concomitantly using strong CYP3A4 inhibitors (e.g., clarithromycin, ketoconazole) because these medications can significantly increase exposure to naloxegol which may precipitate opioid withdrawal symptoms such as hyperhidrosis, chills, diarrhea, abdominal pain, anxiety, irritability, and yawning [see Drug Interactions (7.1) and Clinical Pharmacology… (Naloxegol label, Contraindications)

Avoid use of concomitant drugs known to prolong the QT interval and strong CYP3A4 inhibitors [see Drug Interactions ( 7.1 , 7.2 )] . (Nilotinib label, Boxed warning)

Therefore, the concomitant administration of NYMALIZE and strong CYP3A4 inhibitors should generally be avoided [ see Warnings and Precautions (5.3) ]. (Nimodipine label, Drug interactions)

CYP3A4 inhibitors and inducers : SULAR is substrate of CYP3A4 and coadministration of SULAR with any known inducer or inhibitor of CYP3A4 should be avoided in general. (Nisoldipine label, Drug interactions)

Cytochrome P450 3A4 Interaction The concomitant use of Oxycodone Hydrochloride Oral Solution with all cytochrome P450 3A4 inhibitors may result in an increase in oxycodone plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. (Oxycodone label, Boxed warning)

Cytochrome P450 3A4 Interaction The concomitant use of oxycodone hydrochloride tablets with all cytochrome P450 3A4 inhibitors may result in an increase in oxycodone plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. (Oxycodone and acetaminophen label, Boxed warning)

Cimetidine Clinical Impact: Cimetidine can potentiate opioid-induced respiratory depression. (Oxymorphone label, Drug interactions)

Strong CYP3A4 Inhibitors : Avoid coadministration of VOTRIENT with strong CYP3A4 inhibitors. (Pazopanib label, Drug interactions)

Concomitant use of pimozide with paroxetine and other strong CYP 2D6 inhibitors is contraindicated (See PRECAUTIONS – DRUG INTERACTIONS ). (Pimozide label, Contraindications)

Use of fluvoxamine or other strong CYP1A2 inhibitors should be discontinued prior to administration of ESBRIET and avoided during ESBRIET treatment. (Pirfenidone label, Drug interactions)

Strong CYP1A2 Inhibitors: Avoid concomitant use of strong CYP1A2 inhibitors. (Pomalidomide label, Drug interactions)

Prevention or Management Avoid concomitant use of Noxafil oral suspension with cimetidine or esomeprazole unless the benefit outweighs the risks. (Posaconazole label, Drug interactions)

…outweighs the risks [see Warnings and Precautions ( 5.6 ) and Clinical Pharmacology ( 12.3 ).] 7.2 CYP450 inhibitors Concomitant administration of drugs that decrease the activity of drug metabolizing liver enzymes (CYP450 inhibitors), for example, cimetidine, ketoconazole, itraconazole, erythromycin, and ritonavir may increase plasma concentrations of praziquantel. (Praziquantel label, Drug interactions)

Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex, requiring careful consideration of the effects on the parent drug, codeine, and the active metabolite, morphine. (Promethazine and codeine label, Boxed warning)

• Avoid simultaneous use of propafenone with both a cytochrome P450 2D6 (CYP2D6) inhibitor and a 3A4 inhibitor (CYP3A4). (Propafenone label, Warnings and precautions)

Fluvoxamine (strong CYP1A2 inhibitor): Increases AUC for ramelteon and should not be used in combination. (Ramelteon label, Contraindications)

• Strong CYP3A4 Inhibitors: Avoid concomitant administration. (Rimegepant label, Drug interactions)

Concomitant administration of Risedronate sodium delayed-release and H 2 blockers or PPIs is not recommended. (Risedronate label, Drug interactions)

Use with P-gp and Strong CYP3A Inhibitors or Inducers Avoid concomitant use of XARELTO with known combined P-gp and strong CYP3A inhibitors [see Drug Interactions (7.2) ] . (Rivaroxaban label, Warnings and precautions)

• Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir, ketoconazole): Use not recommended. (Salmeterol label, Drug interactions)

Severe renal impairment (CCr < 30 mL/min) Severe hepatic impairment (Child-Pugh score ≥ 10) Concomitant administration with strong Cytochrome P450 3A4 (CYP3A4) inhibitors (e.g., ketoconazole, clarithromycin, itraconazole, ritonavir) [see DRUG INTERACTIONS (7.1) ] Patients with a history of hypersensitivity to silodosin or any of the ingredients in silodosin capsules… (Silodosin label, Contraindications)

ZOCOR is contraindicated in the following conditions: Concomitant use of strong CYP3A4 inhibitors (select azole anti-fungals, macrolide antibiotics, anti-viral medications, and nefazodone) [see Drug Interactions (7.1) ] . (Simvastatin label, Contraindications)

Interaction with Strong Inhibitors and Inducers of CYP3A4 and/or P-gp Avoid concomitant use of sirolimus with strong inhibitors of CYP3A4 and/or P-gp (such as ketoconazole, voriconazole, itraconazole, erythromycin, telithromycin, or clarithromycin) or strong inducers of CYP3A4 and/or P-gp (such as rifampin or rifabutin) [ see Drug Interactions (7.2) ]. (Sirolimus label, Warnings and precautions)

The dosage of Solifenacin succinate tablets greater than 5 mg once daily is not recommended when concomitantly used with strong CYP3A4 inhibitors [see Dosage and Administration ( 2.4 )] . (Solifenacin label, Drug interactions)

Concomitant use of JOURNAVX with strong CYP3A inhibitors is contraindicated [see Warnings and Precautions (5.1) , Drug Interactions (7.1) ] . (Suzetrigine label, Contraindications)

Tamsulosin hydrochloride capsules should be used with caution in combination with cimetidine, particularly at a dose higher than 0.4 mg (e.g., 0.8 mg) [see Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )] Tamsulosin hydrochloride capsules should not be used in combination with other alpha adrenergic blocking agents [see Drug Interactions ( 7.2 )… (Tamsulosin label, Warnings and precautions)

Strong CYP1A2 inhibitors (e.g., fluvoxamine): Avoid use of HETLIOZ in combination with strong CYP1A2 inhibitors because of increased exposure ( 7.1 , 12.3 ) (Tasimelteon label, Drug interactions)

Avoid co-administration of strong CYP3A4 inhibitors (e.g., itraconazole, clarithromycin, ritonavir) and strong CYP3A4 inducers (e.g., rifampin, phenytoin) with TEPADINA due to the potential effects on efficacy and toxicity [see Clinical Pharmacology ( 12.3 ) ] . (Thiotepa label, Drug interactions)

Zanaflex is contraindicated in patients taking strong CYP1A2 inhibitors [see Drug Interactions ( 7.1 )] . with a history of hypersensitivity to tizanidine or the ingredients in Zanaflex. (Tizanidine label, Contraindications)

…dominant polycystic kidney disease (ADPKD) outside of FDA-approved REMS [see Warnings and Precautions (5.2) ] Unable to sense or respond to thirst Hypovolemic hyponatremia Taking strong CYP3A inhibitors [see Warnings and Precautions (5.5) ] Anuria Hypersensitivity (e.g., anaphylactic shock, rash generalized) to tolvaptan or any components of the product [see Adverse… (Tolvaptan label, Contraindications)

Drugs known to prolong the QT interval and strong CYP3A4 inhibitors should be avoided [see Warnings and Precautions (5.1) ] . (Toremifene label, Boxed warning)

CYP3A inhibitors: Avoid concomitant strong CYP3A inhibitors ( 7.1 ) (Trabectedin label, Drug interactions)

The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with tramadol are complex. (Tramadol label, Boxed warning)

Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with tramadol are complex. (Tramadol and acetaminophen label, Boxed warning)

The use of RALDESY Should be avoided in patients with known QT prolongation or in combination with other drugs that are inhibitors of CYP3A4 (e.g., itraconazole, clarithromycin, voriconazole), or known to prolong QT interval including Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class 3 antiarrhythmics (e.g., amiodarone, sotalol), certain antipsychotic… (Trazodone label, Warnings and precautions)

• Strong CYP3A Inhibitors and Inducers: Avoid coadministration with strong CYP3A inhibitors and inducers. (Tretinoin label, Drug interactions)

Strong CYP 3A Inhibitors Triazolam is contraindicated in patients receiving strong inhibitors of CYP 3A such as ketoconazole, itraconazole, nefazodone, ritonavir, indinavir, nelfinavir, saquinavir, and lopinavir [see Contraindications (4) , Drug Interactions (7.1) ] . (Triazolam label, Warnings and precautions)

UBRELVY is contraindicated: With concomitant use of strong CYP3A4 inhibitors [see Drug Interactions ( 7.1 )] In patients with a history of serious hypersensitivity to ubrogepant or any component of UBRELVY. (Ubrogepant label, Contraindications)

For patients with atopic dermatitis, coadministration of RINVOQ 30 mg once daily with strong CYP3A4 inhibitors is not recommended. (Upadacitinib label, Drug interactions)

Avoid concomitant use of VEPPANU with strong CYP3A inhibitors or drugs known to prolong the QTc interval. (Vepdegestrant label, Warnings and precautions)

Therefore, the concomitant use of strong CYP3A inhibitors with vincristine sulfate should be avoided. (Vincristine label, Drug interactions)

• Strong Inhibitors of CYP2C19 : The recommended dosage is 50 mg once daily or 100 mg once daily for those patients who are not responding to 50 mg once daily. (Abrocitinib label, Drug interactions)

Cimetidine: Increased albendazole sulfoxide concentrations in bile and cystic fluid by about 2-fold in hydatid cyst patients. (Albendazole label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine), may increase the accumulation of metformin. (Alogliptin and metformin label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP450 Inhibitors Grapefruit juice, certain fluoroquinolone and macrolide antibiotics, azole antifungals, cimetidine Increased exposure of amiodarone. (Amiodarone label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Impact of Other Drugs on Amlodipine CYP3A Inhibitors Co-administration with CYP3A inhibitors (moderate and strong) results in increased systemic exposure to amlodipine and may require dose reduction. (Amlodipine label, Drug interactions)

Impact of Other Drugs on Amlodipine CYP3A Inhibitors Co-administration with CYP3A inhibitors (moderate and strong) results in increased systemic exposure to amlodipine and may require dose reduction. (Amlodipine and atorvastatin label, Drug interactions)

CYP3A4 Inhibitors : Coadministration with CYP3A inhibitors (moderate and strong) results in increased systemic exposure to amlodipine and may require dose reduction. (Amlodipine and benazepril label, Drug interactions)

• Increased exposure of amlodipine when coadministered with CYP3A inhibitors Olmesartan medoxomil ( 7.2 ): • Nonsteroidal anti-inflammatory drugs (NSAIDS) may lead to increased risk of renal impairment and loss of antihypertensive effect. (Amlodipine and olmesartan label, Drug interactions)

Amlodipine Impact of Other Drugs on Amlodipine CYP3A Inhibitors Coadministration with CYP3A inhibitors (moderate and strong) results in increased systemic exposure to amlodipine and may require dose reduction. (Amlodipine and valsartan label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Drugs that inhibit CYP1A2 (e.g., fluvoxamine, ciprofloxacin) could increase the exposure of AGRYLIN. (Anagrelide label, Drug interactions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

CYP2D6 inhibitors and CYP3A4 Inhibitors : See full prescribing information for ABILIFY MAINTENA dosage modifications when used concomitantly with CYP2D6 inhibitors and/or CYP3A4 inhibitors for greater than 14 days ( 7.1 ) (Aripiprazole label, Drug interactions)

Reduced plasma concentrations of atazanavir are expected if proton-pump inhibitors, antacids, buffered medications, or H 2 -receptor antagonists are administered with REYATAZ [see Dosage and Administration ( 2.3 , 2.4 , 2.5 and 2.6) ] . (Atazanavir label, Drug interactions)

Strong CYP2D6 Inhibitors Prevention or Management With concomitant use of atomoxetine oral solution and a strong CYP2D6 inhibitor 1 , increase the titration interval [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3) ] . (Atomoxetine label, Drug interactions)

LIPITOR plasma levels can be significantly increased with concomitant administration of inhibitors of CYP3A4 and transporters. (Atorvastatin label, Drug interactions)

CYP3A4/5 Inhibitors Co-administration of ketoconazole, a strong inhibitor of CYP3A4/5, increased the plasma exposure of axitinib in healthy volunteers. (Axitinib label, Drug interactions)

Use of Cytochrome P450 3A4 Inhibitors Ritonavir and other strong cytochrome P450 3A4 (CYP3A4) inhibitors can significantly increase plasma fluticasone propionate exposure, resulting in significantly reduced serum cortisol concentrations [see Drug Interactions ( 7.2 ) and Clinical Pharmacology ( 12.3 )] . (Azelastine and fluticasone label, Warnings and precautions)

Effect of Other Drugs on Bendamustine Hydrochloride Injection CYP1A2 Inhibitors The coadministration of Bendamustine Hydrochloride Injection with CYP1A2 inhibitors may increase bendamustine plasma concentrations and may result in increased incidence of adverse reactions with Bendamustine Hydrochloride Injection [see Clinical Pharmacology (12.3) ] . (Bendamustine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

Strong CYP3A4 Inhibitors: Closely monitor patients with concomitant use. (Bortezomib label, Drug interactions)

Strong CYP2D6 REXULTI may be administered without dosage adjustment in patients with MDD when administered with strong CYP2D6 inhibitors (e.g., paroxetine, fluoxetine). or CYP3A4 inhibitors Administer half of recommended dosage. (Brexpiprazole label, Drug interactions)

CYP2D6 inhibitors may potentiate systemic beta-blockade. (Brimonidine and timolol label, Drug interactions)

Interactions with Strong Cytochrome P450 3A4 Inhibitors Caution should be exercised when considering the co-administration of PULMICORT FLEXHALER with ketoconazole, and other known strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin) because adverse effects related to… (Budesonide label, Warnings and precautions)

Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir): Risk of increased systemic corticosteroid effects. (Budesonide and formoterol label, Warnings and precautions)

Inhibitors of CYP3A4 Clinical Impact: The concomitant use of buprenorphine and CYP3A4 inhibitors can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when an inhibitor is added after a stable dose of buprenorphine and naloxone sublingual tablet is achieved. (Buprenorphine and naloxone label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Other Drugs Cimetidine: Coadministration of buspirone with cimetidine was found to increase C max (40%) and T max (2-fold), but had minimal effects on the AUC of buspirone. (Buspirone label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

It may be necessary to reduce the EQUETRO dose if used concomitantly with inhibitors of CYP3A4 and/or epoxide hydrolase. (Carbamazepine label, Drug interactions)

Clinically Significant Drug Interactions with VRAYLAR Strong or Moderate CYP3A4 Inhibitors Clinical Impact: Concomitant use of VRAYLAR with a strong or moderate CYP3A4 inhibitor increases the exposures of cariprazine and its major active metabolite, didesmethylcariprazine (DDCAR), compared to use of VRAYLAR alone [see Clinical Pharmacology ( 12.3 ) ]. (Cariprazine label, Drug interactions)

Co-administration of CYP2C19 inhibitors, such as omeprazole or fluvoxamine, with carisoprodol could result in increased exposure of carisoprodol and decreased exposure of meprobamate. (Carisoprodol label, Drug interactions)

Greater myelotoxicity (e.g., leukopenia and neutropenia) has been reported when carmustine was combined with cimetidine [see Drug Interactions (7) ] . (Carmustine label, Warnings and precautions)

Cimetidine increased AUC by about 30% but caused no change in C max [see Clinical Pharmacology (12.5) ] . (Carvedilol label, Drug interactions)

Drug Interactions Antacids Concomitant administration of high doses of antacids (sodium bicarbonate and aluminum hydroxide) or H 2 blockers reduces peak plasma levels by 24% to 42% and the extent of absorption by 27% to 32%, respectively. (Cefpodoxime label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

In a drug interaction study, co-administration of orally inhaled ciclesonide and oral ketoconazole, a potent inhibitor of cytochrome P450 3A4, increased the exposure (AUC) of des-ciclesonide by approximately 3.6-fold at steady state, while levels of ciclesonide remained unchanged. (Ciclesonide label, Drug interactions)

Strong and moderate CYP3A4 and CYP2C19 inhibitors: Increase exposure to cilostazol. (Cilostazol label, Drug interactions)

Co-administration with a strong CYP3A4 inhibitor may increase serum levels of cinacalcet. (Cinacalcet label, Drug interactions)

Inhibitors of CYP3A4 and CYP3A5 Inhibitors of CYP3A4 and/or CYP3A5 may increase plasma concentrations of clindamycin [ see Clinical Pharmacology (12.3) ]. (Clindamycin label, Drug interactions)

Strong or Moderate CYP2C19 Inhibitors: Dosage adjustment of SYMPAZAN ® may be necessary ( 7.4 ) (Clobazam label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

• Concomitant use of Strong CYP1A2 Inhibitors: Reduce CLOZARIL dose to one-third when coadministered with strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, enoxacin). (Clozapine label, Drug interactions)

Concomitant administration of itraconazole, a strong CYP3A4 inhibitor, with DUAVEE, resulted in increases in bazedoxifene exposure (40%) and, to a lesser extent, conjugated estrogens exposure (9% for baseline-adjusted total estrone, 5% for total equilin), compared to DUAVEE alone [see Pharmacokinetics (12.3) ] . (Conjugated estrogens and bazedoxifene label, Drug interactions)

…Dysfunction Antibiotics Antineoplastics Antifungals Anti-inflammatory Drugs Gastrointestinal Agents Immunosuppressives Other Drugs ciprofloxacin melphalan amphotericin B azapropazon cimetidine tacrolimus fibric acid derivatives (e.g., bezafibrate, fenofibrate) gentamicin ketoconazole colchicine ranitidine methotrexate tobramycin diclofenac trimethoprim with sulfamethoxazole… (Cyclosporine label, Drug interactions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

OCT2 Inhibitors Concurrent treatment with OCT2 inhibitors, such as cimetidine, may cause increased exposure to dalfampridine [ see Clinical Pharmacology (12.3) ]. (Dalfampridine label, Drug interactions)

…renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE] inhibitors, such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical Pharmacology (12.3) ] . (Dapagliflozin and metformin label, Drug interactions)

CYP3A4 Inhibitors The systemic exposure of darifenacin from darifenacin extended-release tablets is increased in the presence of CYP3A4 inhibitors. (Darifenacin label, Drug interactions)

Co-administration of darunavir and ritonavir and other drugs that inhibit CYP3A, or P-gp may decrease the clearance of darunavir and ritonavir and may result in increased plasma concentrations of darunavir and ritonavir (see Table 10 ). (Darunavir label, Drug interactions)

Co-administration of PREZCOBIX or PREZCOBIX PED and other drugs that inhibit CYP3A may result in increased plasma concentrations of darunavir and cobicistat (see Table 2 ). (Darunavir and cobicistat label, Drug interactions)

Moderate or strong CYP3A4 inhibitors: Give one third of the recommended dosage of EMFLAZA ( 7.1 ) (Deflazacort label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations. (Desogestrel and ethinyl estradiol label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Concomitant use of strong CYP2D6 inhibitors: Maximum recommended dose of AUSTEDO XR or AUSTEDO is 36 mg per day ( 2.3 , 7.1 ) (Deutetrabenazine label, Drug interactions)

CYP2C19 or CYP3A4 Inhibitors Clinical Impact: Increased exposure of dexlansoprazole is expected when used concomitantly with strong inhibitors [see Clinical Pharmacology (12.3) ] . (Dexlansoprazole label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Co-administration of PIFELTRO and drugs that are inhibitors of CYP3A may result in increased plasma concentrations of doravirine. (Doravirine label, Drug interactions)

CYP2D6 inhibitors may potentiate systemic beta-blockade. (Dorzolamide and timolol label, Drug interactions)

Cimetidine: In healthy volunteers, the administration of a single 1 mg dose of doxazosin on day 1 of a four-day regimen of oral cimetidine (400 mg twice daily) resulted in a 10% increase in mean AUC of doxazosin, and a slight but not significant increase in mean C max and mean half-life of doxazosin. (Doxazosin label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Monitor for increased dronabinol-related adverse reactions when dronabinol oral solution is co-administered with inhibitors of CYP2C9 (e.g., amiodarone, fluconazole) and inhibitors of CYP3A4 enzymes (e.g., ketoconazole, itraconazole, clarithromycin, ritonavir, erythromycin, grapefruit juice). (Dronabinol label, Drug interactions)

Effects of Other Drugs on Dronedarone Ketoconazole and Other Potent CYP3A Inhibitors Concomitant use of ketoconazole as well as other potent CYP3A inhibitors such as itraconazole, voriconazole, ritonavir, clarithromycin, and nefazodone is contraindicated because exposure to dronedarone is significantly increased [see Contraindications (4) , Clinical Pharmacology… (Dronedarone label, Drug interactions)

Consider monitoring serum potassium concentration in high-risk patients who take a strong CYP3A4 inhibitor long-term and concomitantly. (Drospirenone and ethinyl estradiol label, Warnings and precautions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

Concomitant Use with CYP3A Inhibitors Exposure to elexacaftor, tezacaftor and ivacaftor are increased when used concomitantly with strong or moderate CYP3A inhibitors. (Elexacaftor, tezacaftor, and ivacaftor label, Warnings and precautions)

Coadministration of GENVOYA with other drugs that inhibit CYP3A may decrease the clearance and increase the plasma concentration of cobicistat. (Elvitegravir, cobicistat, emtricitabine, and tenofovir label, Drug interactions)

…tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical Pharmacology (12.3) ] . (Empagliflozin and metformin label, Drug interactions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP2C19 Substrates APTIOM can inhibit CYP2C19, which can cause increased plasma concentrations of drugs that are metabolized by this isoenzyme (e.g., phenytoin, clobazam, and omeprazole) [see Clinical Pharmacology ( 12.3 )]. (Eslicarbazepine label, Drug interactions)

Inhibitors of CYP3A4 such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice may increase plasma concentrations of estrogens and may result in side effects. (Estradiol label, Drug interactions)

…exposure at steady state. [See Clinical Pharmacology (12.3).] Substances Increasing the Systemic Exposure of COCs (enzyme inhibitors): Concomitant administration of moderate or strong CYP3A4 inhibitors like azole antifungals (for example, ketoconazole, itraconazole, voriconazole, fluconazole), verapamil, macrolides (for example, clarithromycin, erythromycin), diltiazem,… (Estradiol and dienogest label, Drug interactions)

Inducers and/or inhibitors of CYP3A4 may affect estrogen drug metabolism and decrease or increase the estrogen plasma concentration. (Estradiol and norethindrone label, Drug interactions)

The dose of LUNESTA should be reduced in patients who are administered potent inhibitors of CYP3A4, such as ketoconazole, while taking LUNESTA. (Eszopiclone label, Warnings and precautions)

Concomitant administration of strong or moderate CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma estrogen and/or progestin concentrations. (Etonogestrel and ethinyl estradiol label, Drug interactions)

CCR5 antagonists maraviroc ↔ etravirine ↓ maraviroc When Etravirine is co-administered with maraviroc in the absence of a potent CYP3A inhibitor (e.g., ritonavir boosted protease inhibitor), the recommended dose of maraviroc is 600 mg twice daily. (Etravirine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Cimetidine - Coadministration of felodipine with cimetidine (a non-specific CYP-450 inhibitor) resulted in an increase of approximately 50% in the AUC and the C max , of felodipine. (Felodipine label, Drug interactions)

In healthy subjects receiving cimetidine (1 gm daily) for one week, plasma flecainide levels increased by about 30% and half-life increased by about 10%. (Flecainide label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Reciprocal interactions may occur with concomitant use of fomepizole and drugs that increase or inhibit the cytochrome P450 system (e.g., phenytoin, carbamazepine, cimetidine, ketoconazole), though this has not been studied. (Fomepizole label, Drug interactions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

Histamine H 2 -receptor antagonists: Cimetidine, famotidine, nizatidine, ranitidine a Fosamprenavir calcium: ↓ Amprenavir Fosamprenavir calcium/ritonavir: Interaction not evaluated Use with caution. (Fosamprenavir label, Drug interactions)

In separate single or multiple dose pharmacokinetic interaction studies with chlorthalidone, nifedipine, propranolol, hydrochlorothiazide, cimetidine, metoclopramide, propantheline, digoxin, and warfarin, the bioavailability of fosinoprilat was not altered by coadministration of fosinopril with any one of these drugs. (Fosinopril label, Drug interactions)

…Azoles Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole Antineoplastic agents Capecitabine, fluorouracil Antidepressants Fluoxetine, fluvoxamine, sertraline Gastric acid reducing agents H 2 antagonists (cimetidine), omeprazole Sulfonamides Sulfamethizole, sulfaphenazole, sulfadiazine, sulfamethoxazole-trimethoprim Other Acute alcohol intake, amiodarone,… (Fosphenytoin label, Drug interactions)

• CYP3A4 Inhibitor: Monitor adverse reactions if concomitant use with IRESSA. (Gefitinib label, Drug interactions)

…glimepiride, increasing the susceptibility to and/or intensity of hypoglycemia: oral anti-diabetic medications, pramlintide acetate, insulin, angiotensin converting enzyme (ACE) inhibitors, H 2 receptor antagonists, fibrates, propoxyphene, pentoxifylline, somatostatin analogs, anabolic steroids and androgens, cyclophosphamide, phenyramidol, guanethidine, fluconazole, sulfinpyrazone,… (Glimepiride label, Drug interactions)

…angiotensin II receptor blocking agents, disopyramide, fibrates, fluoxetine, monoamine oxidase inhibitors, pentoxifylline, pramlintide, propoxyphene, salicylates, somatostatin analogs (e.g., octreotide), sulfonamide antibiotics, nonsteroidal anti-inflammatory agents, chloramphenicol, probenecid, coumarins, voriconazole, H2 receptor antagonists, and quinolones. (Glipizide label, Drug interactions)

…drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis. (Glipizide and metformin label, Precautions)

Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin. (Glyburide and metformin label, Drug interactions)

…Interactions: Effect of other Drugs on INTUNIV Concomitant Drug Name or Drug Class Clinical Rationale and Magnitude of Drug Interaction Clinical Recommendation Strong and moderate CYP3A4 inhibitors, e.g., ketoconazole, fluconazole Guanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be significantly affected resulting in an increase… (Guanfacine label, Drug interactions)

The effect of CYP3A4 inhibition and of decreased CYP2D6 enzyme may be additive. (Haloperidol label, Drug interactions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

Concomitant administration of inhibitors of CYP3A4 may lead to increases in serum concentrations of ALKINDI SPRINKLE and increase the risk of adverse reactions associated with the use of excessive doses. (Hydrocortisone label, Drug interactions)

H2 Blockers In healthy volunteers, co-administration with ranitidine resulted in a 20% increased bioavailability of ibandronate, which was not considered to be clinically relevant (see CLINICAL PHARMACOLOGY [12.3] ) . (Ibandronate label, Drug interactions)

• CYP3A4 Inhibitors: Use in combination with CYP3A4 inhibitors could decrease the effectiveness of ifosfamide. (Ifosfamide label, Drug interactions)

The dose of FANAPT should be reduced in patients co-administered a strong CYP2D6 or CYP3A4 inhibitor. (Iloperidone label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Cimetidine: In a study in healthy volunteers, a one-week course of cimetidine at 400 mg b.i.d. with a single 5 mg dose of isradipine on the sixth day showed an increase in isradipine mean peak plasma concentrations (36%) and significant increase in area under the curve (50%). (Isradipine label, Drug interactions)

Potential for other drugs to affect ivacaftor CYP3A inhibitors: Reduce KALYDECO dosage in patients aged 6 months and older when co-administered with strong CYP3A inhibitors (e.g., ketoconazole) or moderate CYP3A inhibitors (e.g., fluconazole). (Ivacaftor label, Drug interactions)

Drugs that may decrease ketoconazole plasma concentrations Drugs that reduce the gastric acidity (e.g., acid neutralizing medicines such as aluminum hydroxide, or acid secretion suppressors such as H 2 -receptor antagonists and proton pump inhibitors) impair the absorption of ketoconazole from ketoconazole tablets. (Ketoconazole label, Drug interactions)

Strong CYP3A4 or CYP2C9 Inhibitors Patients with renal or hepatic impairment who are taking strong inhibitors of CYP3A4 and CYP2C9 may have a significant increase in exposure to VIMPAT. (Lacosamide label, Drug interactions)

CYP2C19 or CYP3A4 Inhibitors Clinical Impact: Increased exposure of lansoprazole is expected when used concomitantly with strong inhibitors [see Clinical Pharmacology (12.3) ] . (Lansoprazole label, Drug interactions)

Concomitant Drug Class: Drug Name Effect on Concentration ↓ = decrease, ↑ = increase Clinical Comment tenofovir DF = tenofovir disoproxil fumarate Acid Reducing Agents: ↓ ledipasvir Ledipasvir solubility decreases as pH increases. (Ledipasvir and sofosbuvir label, Drug interactions)

In patients taking ARAVA, exposure of drugs which are OAT3 substrates (e.g., cefaclor, cimetidine, ciprofloxacin, penicillin G, ketoprofen, furosemide, methotrexate, zidovudine) may be increased. (Leflunomide label, Drug interactions)

However, these changes do not warrant dosage adjustment for Levofloxacin in 5% Dextrose Injection when probenecid or cimetidine is co-administered. (Levofloxacin label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP3A inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice The effect of grapefruit juice on CYP3A4 enzymes (e.g., strong vs. moderate inhibition) depends on its brand, concentration, and preparation. , or ketoconazole may increase systemic exposure of the estrogen and/or progestin component of CHCs. (Levonorgestrel and ethinyl estradiol label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical Pharmacology (12.3) ] . (Linagliptin and metformin label, Drug interactions)

CYP2D6 Inhibitors : Concomitant use of paroxetine resulted in increased plasma levels of Lofexidine tablets. (Lofexidine label, Drug interactions)

Drug Interactions Effects of Other Drugs on Loperamide Concomitant use of loperamide hydrochloride capsules with inhibitors of CYP3A4 (e.g., itraconazole) or CYP2C8 (e.g., gemfibrozil) or inhibitors of P-glycoprotein (e.g., quinidine, ritonavir) can increase exposure to loperamide. (Loperamide label, Drug interactions)

Potential for KALETRA to Affect Other Drugs Lopinavir/ritonavir is an inhibitor of CYP3A and may increase plasma concentrations of agents that are primarily metabolized by CYP3A. (Lopinavir and ritonavir label, Drug interactions)

Strong CYP3A4 inhibitors: Recommended dosage is 10.5 mg once daily. (Lumateperone label, Drug interactions)

Ketoconazole (Potent Inhibitor of CYP3A4) Coadministration of a single 500 mg oral dose of mefloquine with 400 mg of ketoconazole once daily for 10 days in 8 healthy volunteers resulted in an increase in the mean C max and AUC of mefloquine by 64% and 79%, respectively, and an increase in the mean elimination half-life of mefloquine from 322 hours to 448 hours. (Mefloquine label, Drug interactions)

Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin. (Metformin label, Drug interactions)

• Strong CYP2D6 inhibitors (e.g., quinidine, bupropion, fluoxetine, and paroxetine) : See Full Prescribing Information for recommended dosage reductions. (Metoclopramide label, Drug interactions)

CYP2D6 inhibitors: Increased metoprolol concentration. (Metoprolol and hydrochlorothiazide label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Concurrent administration of cimetidine and mexiletine has been reported to increase, decrease, or leave unchanged mexiletine plasma levels; therefore patients should be followed carefully during concurrent therapy. (Mexiletine label, Drug interactions)

The effect of single oral doses of 800 mg cimetidine and 300 mg ranitidine on steady-state concentrations of midazolam was examined in a randomized crossover study (n=8). (Midazolam label, Drug interactions)

…mifepristone is contraindicated. [See Contraindications (4.3)] 5.6 Use of Strong CYP3A Inhibitors Mifepristone should be used with caution in patients taking ketoconazole and other strong inhibitors of CYP3A, such as itraconazole, nefazodone, ritonavir, nelfinavir, indinavir, atazanavir, amprenavir, fosamprenavir, clarithromycin, conivaptan, lopinavir/ritonavir, posaconazole,… (Mifepristone label, Warnings and precautions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir): Risk of increased systemic corticosteroid effects. (Mometasone label, Warnings and precautions)

Intervention: Evaluate patients for increased respiratory and CNS depression when Morphine Sulfate Oral Solution is used concomitantly with cimetidine. (Morphine label, Drug interactions)

Anaphylactic Shock and Hypersensitivity Reactions: Premedicate all patients with a combination of an H1-antihistamine, an H2 blocker, and a leukotriene inhibitor prior to each APHEXDA dose. (Motixafortide label, Warnings and precautions)

Moderate (e.g., fluconazole, atazanavir, aprepitant, diltiazem, erythromycin) and Strong (e.g., itraconazole, ketoconazole, clarithromycin, ritonavir, saquinavir) CYP3A Inhibitors Clinical Impact Increase in plasma naldemedine concentrations [see Clinical Pharmacology (12.3) ] Intervention Monitor for potential naldemedine-related adverse reactions [see Adverse… (Naldemedine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP2C19 or CYP3A4 Inhibitors Clinical Impact : Increased exposure of esomeprazole [see Clinical Pharmacology (12.3) ]. (Naproxen and esomeprazole label, Drug interactions)

Use with CYP2D6 Inhibitors Nebivolol exposure increases with inhibition of CYP2D6 [see Drug Interactions ( 7 ) ] . (Nebivolol label, Warnings and precautions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

• Cimetidine increases oral nicardipine plasma levels. (Nicardipine label, Drug interactions)

…tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these… (Cimetidine label, Drug interactions)

Coadministration of P-gp and CYP3A4 inhibitors may increase nintedanib exposure. (Nintedanib label, Drug interactions)

CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations. (Norelgestromin and ethinyl estradiol label, Drug interactions)

Substances increasing the systemic concentrations of HCs: Co-administration of certain HCs and strong or moderate CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase the systemic concentrations of progestins, including norethindrone. (Norethindrone label, Drug interactions)

CYP3A4 inhibitors such as itraconazole or ketoconazole may increase plasma hormone levels. (Norethindrone and ethinyl estradiol label, Drug interactions)

CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations. (Norgestimate and ethinyl estradiol label, Drug interactions)

Concomitant administration of CYP3A4 inhibitors such as itraconazole, fluconazole, grapefruit juice or ketoconazole may increase plasma hormone concentrations. (Norgestrel and ethinyl estradiol label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Proton Pump Inhibitors, H2-receptor Antagonists, or Antacids: may decrease bioavailability of MYCAPSSA and the MYCAPSSA dose may need to be increased (‎ 7 ). (Octreotide label, Drug interactions)

Inhibitors of CYP1A2 Fluvoxamine: Fluvoxamine, a CYP1A2 inhibitor, decreases the clearance of olanzapine. (Olanzapine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Risk of Use in Patients with Decreased Cytochrome P450 2D6 Function or Concomitant Use or Discontinuation with Cytochrome P450 3A4 Inhibitors and Inducers Risk of Increased Oliceridine Plasma Concentrations Increased plasma concentrations of oliceridine, which may result in prolonged opioid adverse reactions and exacerbated respiratory depression, may occur when… (Oliceridine label, Warnings and precautions)

• Increased amlodipine exposure when coadministered with CYP3A inhibitors Hydrochlorothiazide ( 7.3 ): • Antidiabetic drugs: Dosage adjustment of antidiabetic may be required. (Olmesartan, amlodipine, and hydrochlorothiazide label, Drug interactions)

Concomitant administration of CYP3A4 inhibitors may inhibit the metabolism of, and increase the mometasone furoate plasma concentration and potentially increase the risk for adverse reactions. (Olopatadine and mometasone label, Drug interactions)

CYP2C19 or CYP3A4 Inhibitors Clinical Impact: Increased exposure of omeprazole [see Clinical Pharmacology ( 12.3 )] . (Omeprazole label, Drug interactions)

CYP2C19 or CYP3A4 Inhibitors Clinical Impact: Increased exposure of omeprazole [see Clinical Pharmacology ( 12.3 )] . (Omeprazole and sodium bicarbonate label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Co-administration with strong cytochrome P450 (CYP) 3A4 inhibitors (e.g., ketoconazole) increases the systemic exposure of oxybutynin. (Oxybutynin label, Drug interactions)

Exposure of Paricalcitol Injection will increase upon coadministration with strong CYP3A inhibitors [see Clinical Pharmacology (12.3) ] . (Paricalcitol label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing… (Cimetidine label, Drug interactions)

Strong CYP3A4 Inhibitors: Reduce NUPLAZID dose to 10 mg once daily. (Pimavanserin label, Drug interactions)

…tablets, increasing the susceptibility to and/or intensity of hypoglycemia: oral anti-diabetic medications, pramlintide acetate, insulin, angiotensin converting enzyme (ACE) inhibitors, H2 receptor antagonists, fibrates, propoxyphene, pentoxifylline, somatostatin analogs, anabolic steroids and androgens, cyclophosphamide, phenyramidol, guanethidine, fluconazole, sulfinpyrazone,… (Pioglitazone and glimepiride label, Drug interactions)

Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine), may increase the accumulation of metformin. (Pioglitazone and metformin label, Drug interactions)

Strong CYP2D6 Inhibitors: Increased exposure of WAKIX; reduce the maximum recommended dose of WAKIX by half ( 2.6 , 7.1 ) (Pitolisant label, Drug interactions)

…develop drowsiness and specifically ask about factors that may increase the risk for somnolence with pramipexole dihydrochloride tablets such as the use of concomitant sedating medications or alcohol, the presence of sleep disorders, and concomitant medications that increase pramipexole plasma levels (e.g., cimetidine) [ see Clinical Pharmacology ( 12.3 ) ]. (Pramipexole label, Warnings and precautions)

CYP 3A4 inhibitors (e.g., ketoconazole, macrolide antibiotics): Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60% leading to an increased risk of corticosteroid side effects. (Prednisolone label, Drug interactions)

CYP 3A4 Inhibitors (e.g., Ketoconazole, Macrolide Antibiotics) Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60% leading to increased risk of corticosteroid side effects. (Prednisone label, Drug interactions)

Effects of Other Drugs on the Pharmacokinetics of Primaquine Strong CYP2D6 Inhibitors Published clinical and non-clinical reports indicate reduced CYP2D6 activity may decrease the formation of active metabolites of primaquine, which may reduce antimalarial efficacy of Primaquine phosphate Tablets (see CLINICAL PHARMACOLOGY, Pharmacogenomics ). (Primaquine label, Drug interactions)

…Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood… (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

• Concomitant use of strong CYP3A4 inhibitors: Reduce quetiapine dose to one‑sixth when coadministered with strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) ( 2.5 , 7.1 , 12.3 ) (Quetiapine label, Drug interactions)

By pharmacokinetic mechanisms that are not well understood, quinidine levels are increased by coadministration of amiodarone or cimetidine . (Quinidine label, Drug interactions)

Histamine H 2 -Receptor Blockers [Cimetidine, Ranitidine (Nonspecific CYP450 Inhibitors)] In healthy subjects who were given a single oral 600 mg dose of quinine sulfate after pretreatment with cimetidine (200 mg three times daily and 400 mg at bedtime for 7 days) or ranitidine (150 mg twice daily for 7 days), the apparent oral clearance of quinine decreased… (Quinine label, Drug interactions)

Ciprofloxacin or Other CYP1A2 Inhibitors Rasagiline plasma concentrations may increase up to 2 fold in patients using concomitant ciprofloxacin and other CYP1A2 inhibitors. (Rasagiline label, Warnings and precautions)

CYP2C8 and CYP3A4 Inhibitors Intervention: Repaglinide tablets dose reductions and increased frequency of glucose monitoring may be required when co‑administered. (Repaglinide label, Drug interactions)

Effect of Other Drugs on Rifabutin Pharmacokinetics Some drugs that inhibit CYP3A may significantly increase the plasma concentration of rifabutin. (Rifabutin label, Drug interactions)

Coadministration of EDURANT or EDURANT PED and drugs that inhibit CYP3A may result in increased plasma concentrations of rilpivirine. (Rilpivirine label, Drug interactions)

Strong to moderate CYP1A2 inhibitors: Co-administration may increase TIGLUTIK-associated adverse reactions ( 7.1 ) (Riluzole label, Drug interactions)

Cimetidine and ranitidine increase the bioavailability of risperidone. (Risperidone label, Drug interactions)

Use with inhibitors of CYP3A4 or dual inhibitors of CYP3A4 and CYP1A2 (e.g., erythromycin, ketoconazole, fluvoxamine, enoxacin, cimetidine) will increase roflumilast systemic exposure and may result in increased adverse reactions. (Roflumilast label, Drug interactions)

• Monitor for toxicities related to increased romidepsin exposure when co-administering romidepsin with strong CYP3A4 inhibitors ( 7.2 ). (Romidepsin label, Drug interactions)

Therefore, if therapy with a drug known to be a potent inducer or inhibitor of CYP1A2 is stopped or started during treatment with ropinirole, adjustment of the dose of ropinirole may be required. (Ropinirole label, Drug interactions)

In vivo, the plasma clearance of ropivacaine was reduced by 70% during coadministration of fluvoxamine (25 mg bid for 2 days), a selective and potent CYP1A2 inhibitor. (Ropivacaine label, Drug interactions)

Strong CYP3A4 Inhibitors: Reduce, interrupt, or discontinue JAKAFI/JAKAFI XR doses as recommended except in patients with acute or chronic graft-versus-host-disease. (Ruxolitinib label, Drug interactions)

Strong Inhibitors of CYP3A4/5 Enzymes Ketoconazole significantly increased saxagliptin exposure. (Saxagliptin label, Drug interactions)

…renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [ see Clinical Pharmacology (12.3) ]. (Saxagliptin and metformin label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin) increase SILDENAFIL ORAL FILM exposure. (Sildenafil label, Drug interactions)

Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin. (Sitagliptin and metformin label, Drug interactions)

Clinical Effect/Recommendation Acid Reducing Agents: ↓ velpatasvir Velpatasvir solubility decreases as pH increases. (Sofosbuvir and velpatasvir label, Drug interactions)

Drug Interactions Some studies have shown that simultaneous sucralfate administration in healthy volunteers reduced the extent of absorption (bioavailability) of single doses of the following: cimetidine, digoxin, fluoroquinolone antibiotics, ketoconazole, l-thyroxine, phenytoin, quinidine, ranitidine, tetracycline, and theophylline. (Sucralfate label, Drug interactions)

Monitor QT interval more frequently when SUTENT is concomitantly administered with strong CYP3A4 inhibitors or drugs known to prolong QT interval. (Sunitinib label, Warnings and precautions)

The risk for nephrotoxicity may increase when ASTAGRAF XL is concomitantly administered with CYP3A inhibitors (by increasing tacrolimus whole blood concentrations) or drugs associated with nephrotoxicity (e.g., aminoglycosides, ganciclovir, amphotericin B, cisplatin, nucleotide reverse transcriptase inhibitors, protease inhibitors). (Tacrolimus label, Warnings and precautions)

…Physicians should be aware that CIALIS for once daily use provides continuous plasma tadalafil levels and should consider this when evaluating the potential for interactions with medications (e.g., nitrates, alpha-blockers, anti-hypertensives and potent inhibitors of CYP3A4) and with substantial consumption of alcohol [see Drug Interactions ( 7.1 , 7.2 , 7.3 )] . (Tadalafil label, Warnings and precautions)

CYP3A4 Inhibitors Co-administration of a 180 mg daily dose of diltiazem with 5 mg amlodipine in elderly hypertensive patients resulted in a 60% increase in amlodipine systemic exposure. (Telmisartan and amlodipine label, Drug interactions)

The pharmacokinetic profile of temazepam does not appear to be altered by orally administered cimetidine dosed according to labeling. (Temazepam label, Drug interactions)

…physician, treatment may be resumed with the administration of an H 1 -receptor antagonist (such as diphenhydramine), if not previously administered [see Dosage and Administration (2.2) ] , and/or an H 2 -receptor antagonist (such as intravenous famotidine 20 mg or intravenous ranitidine 50 mg) approximately 30 minutes before restarting the TORISEL infusion. (Temsirolimus label, Warnings and precautions)

Terbinafine clearance is increased 100% by rifampin, a CYP450 enzyme inducer, and decreased 33% by cimetidine, a CYP450 enzyme inhibitor. (Terbinafine label, Drug interactions)

In patients taking AUBAGIO, exposure of drugs which are OAT3 substrates (e.g., cefaclor, cimetidine, ciprofloxacin, penicillin G, ketoprofen, furosemide, methotrexate, zidovudine) may be increased. (Teriflunomide label, Drug interactions)

• Do not exceed 50 mg/day and the maximum single dose should not exceed 25 mg if administered in conjunction with a strong CYP2D6 inhibitor (e.g., fluoxetine, paroxetine). (Tetrabenazine label, Warnings and precautions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP2D6 Inhibitors Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with CYP2D6 inhibitors (e.g., quinidine) and timolol. (Timolol label, Drug interactions)

Simultaneous administration of drugs that inhibit the activity of liver microsomal enzymes, i.e., CYP3A4 inhibitors such as cimetidine and ketoconazole, may prolong the half-life and decrease the plasma clearance of tinidazole, increasing the plasma concentrations of tinidazole. (Tinidazole label, Drug interactions)

…modification of XELJANZ/XELJANZ XR is recommended [see Dosage and Administration (2) , Clinical Pharmacology, Figure 3 (12.3) ] Moderate CYP3A4 Inhibitors Concomitantly Used with Strong CYP2C19 Inhibitors (e.g., fluconazole) Clinical Impact Increased exposure to tofacitinib Intervention Dosage modification of XELJANZ/XELJANZ XR is recommended [see Dosage and Administration… (Tofacitinib label, Drug interactions)

Drug Interactions CYP3A4 Inhibitors Ketoconazole, an inhibitor of the drug metabolizing enzyme CYP3A4, significantly increased plasma concentrations of tolterodine when coadministered to subjects who were poor metabolizers (see CLINICAL PHARMACOLOGY, Variability in Metabolism and Drug-Drug Interactions ). (Tolterodine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Co-administration of other strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin, cobicistat-containing products) with KENALOG-40 Injection may cause increased plasma concentration of triamcinolone leading to adverse reactions. (Triamcinolone label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Increase in Plasma Concentrations of ella Associated with Co-Administered Drugs CYP3A4 inhibitors such as itraconazole or ketoconazole increase plasma concentrations of ella [see Pharmacokinetics (12.3) ] . (Ulipristal label, Drug interactions)

Drug Interactions with Strong Cytochrome P450 3A4 Inhibitors Caution should be exercised when considering the coadministration of Umeclidinium and Vilanterol ELLIPTA with ketoconazole and other known strong cytochrome P450 3A4 (CYP3A4) inhibitors (including, but not limited to, ritonavir, clarithromycin, conivaptan, indinavir, itraconazole, lopinavir, nefazodone,… (Umeclidinium and vilanterol label, Warnings and precautions)

In patients taking a strong CYP2D6 or CYP3A4 inhibitor, or who are CYP2D6 poor metabolizers, INGREZZA and INGREZZA SPRINKLE concentrations may be higher and QT prolongation clinically significant [see Clinical Pharmacology ( 12.2 )] . (Valbenazine label, Warnings and precautions)

Potential for Drug Interactions with Strong or Moderate CYP3A4 Inhibitors Concomitant administration with strong CYP3A4 inhibitors (such as ritonavir, indinavir, cobicistat, ketoconazole) or moderate CYP3A4 inhibitors (such as erythromycin) increases plasma concentrations of vardenafil. (Vardenafil label, Warnings and precautions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

CYP2D6 Substrates Clinical Impact Viloxazine is a weak inhibitor of CYP2D6, and increases the exposure of CYP2D6 substrates when coadministered [see Clinical Pharmacology (12.3) ] . (Viloxazine label, Drug interactions)

Inhibitors of CYP3A4: May cause earlier onset and/or increased severity of adverse reactions ( 7.1 ) (Vinorelbine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Drug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination… (Cimetidine label, Drug interactions)

As zafirlukast is known to be an inhibitor of CYP3A4 in vitro , it is reasonable to employ appropriate clinical monitoring when these drugs are coadministered with zafirlukast. (Zafirlukast label, Precautions)

Concomitant administration of zaleplon (10 mg) and cimetidine (800 mg) produced an 85% increase in the mean C max and AUC of zaleplon. (Zaleplon label, Drug interactions)

Ketoconazole Ketoconazole, a potent inhibitor of CYP3A4, at a dose of 400 mg QD for 5 days, increased the AUC and C max of ziprasidone by about 35 to 40%. (Ziprasidone label, Drug interactions)

If cimetidine and zolmitriptan are used concomitantly, limit the maximum single dose of zolmitriptan to 2.5 mg, not to exceed 5 mg in any 24-hour period [see Dosage and Administration, ( 2.4 ) and Clinical Pharmacology ( 12.3 ) ]. (Zolmitriptan label, Drug interactions)

CYP3A4 Inhibitors Ketoconazole Ketoconazole, a potent CYP3A4 inhibitor, increased the exposure to and pharmacodynamic effects of zolpidem. (Zolpidem label, Drug interactions)

Other: There appears to be no pharmacokinetic interaction between acitretin and cimetidine, digoxin, or glyburide. (Acitretin label, Drug interactions)

Strong CYP1A2 Inhibitors (e.g., Fluvoxamine) SAPHRIS is metabolized by CYP1A2. (Asenapine label, Drug interactions)

Benazepril Benazepril has been used concomitantly with beta-adrenergic-blocking agents, calcium-blocking agents, cimetidine, diuretics, digoxin, hydralazine, and naproxen without evidence of clinically important adverse interactions. (Benazepril and hydrochlorothiazide label, Drug interactions)

Drug Interactions The following drugs have been coadministered with betaxolol and have not altered its pharmacokinetics: cimetidine, nifedipine, chlorthalidone, and hydrochlorothiazide. (Betaxolol label, Drug interactions)

Drug Interactions Antacids The extent of absorption of cefaclor extended-release tablets is diminished if magnesium or aluminum hydroxide-containing antacids are taken within 1 hour of administration; H 2 blockers do not alter either the rate or the extent of absorption of cefaclor extended-release tablets. (Cefaclor label, Drug interactions)

CYP2D6 substrates Clinical Impact: In vitro studies indicate that celecoxib, although not a substrate, is an inhibitor of CYP2D6. (Celecoxib label, Drug interactions)

Drugs which inhibit CYP2D6 and CYP3A3/4 also inhibit the metabolism of cevimeline. (Cevimeline label, Drug interactions)

Clarithromycin and other macrolides are known to inhibit CYP3A and Pgp. (Clarithromycin label, Drug interactions)

The selective serotonin reuptake inhibitors sertraline (weak CYP3A4 inducer) and fluoxetine (CYP2D6 inhibitor), and the anti-epileptic drug felbamate (CYP2C19 inhibitor and CYP3A4 inducer) do not affect the pharmacokinetics of clonazepam. (Clonazepam label, Drug interactions)

Although potent inhibitors of cytochrome P450 3A4 (e.g., ketoconazole) have not been studied clinically, in vitro studies have shown that erythromycin and oleandomycin inhibit the metabolism of disopyramide. (Disopyramide label, Drug interactions)

The effect of potent CYP3A4 inhibitors on dutasteride has not been studied. (Dutasteride label, Drug interactions)

TAF is a weak inhibitor of CYP3A in vitro . (Emtricitabine and tenofovir label, Drug interactions)

Effects of Other Drugs on HALAVEN No drug-drug interactions are expected with CYP3A4 inhibitors, CYP3A4 inducers or P-glycoprotein (P-gp) inhibitors. (Eribulin label, Drug interactions)

Clinical interaction studies of famciclovir with cimetidine and promethazine, in vitro inhibitors of aldehyde oxidase, did not show relevant effects on the formation of penciclovir. (Famciclovir label, Drug interactions)

Other The bioavailability of unbound fosinoprilat is not altered by coadministration of fosinopril with aspirin, chlorthalidone, cimetidine, digoxin, metoclopramide, nifedipine, propranolol, propantheline, or warfarin . (Fosinopril and hydrochlorothiazide label, Drug interactions)

Cimetidine In the presence of cimetidine at 300 mg four times a day (N=12), the mean apparent oral clearance of gabapentin fell by 14% and creatinine clearance fell by 10%. (Gabapentin label, Drug interactions)

(E) In vitro studies of CYP enzymes, UGTA enzymes and OATP1B1 transporter In vitro studies have shown that gemfibrozil is an inhibitor of CYP1A2, CYP2C8, CYP2C9, CYP2C19, OATP1B1, and UDP-glucuronosyltransferase (UGT) 1A1 and 1A3 (see WARNINGS ). (Gemfibrozil label, Drug interactions)

Acid-reducing medicines lower stomach acid and can reduce the amount of iron absorbed from supplements and food. (NIH Office of Dietary Supplements, Iron)

Effect of SUNLENCA on Other Drugs Lenacapavir is a moderate inhibitor of CYP3A. (Lenacapavir label, Drug interactions)

Antipyrine, Azithromycin, Cimetidine, Erythromycin, Ketoconazole, Theophylline, and Pseudoephedrine Pharmacokinetic interaction studies performed with racemic cetirizine demonstrated that cetirizine did not interact with antipyrine, pseudoephedrine, erythromycin, azithromycin, ketoconazole, and cimetidine. (Levocetirizine label, Drug interactions)

• CYP2D6 inhibitors: As meclizine is metabolized by CYP2D6, there is a potential for drug-drug interactions between meclizine hydrochloride and CYP2D6 inhibitors ( 7.2 ). (Meclizine label, Drug interactions)

Effect of Other Drugs on the Metabolism of Donepezil Inhibitors of CYP3A4 (e.g., ketoconazole) and CYP2D6 (e.g., quinidine), inhibit donepezil metabolism in vitro . (Memantine and donepezil label, Drug interactions)

…for Drug Interaction: It appears possible, although there is no supporting experimental evidence, that the high renal clearance of desglymidodrine (a base) is due to active tubular secretion by the base-secreting system also responsible for the secretion of such drugs as metformin, cimetidine, ranitidine, procainamide, triamterene, flecainide, and quinidine. (Midodrine label, Precautions)

Moexipril hydrochloride has been used in clinical trials concomitantly with calcium-channel-blocking agents, diuretics, H 2 blockers, digoxin, oral hypoglycemic agents, and cholesterol-lowering agents. (Moexipril label, Drug interactions)

Potential for PAXLOVID to Affect Other Drugs PAXLOVID (nirmatrelvir co-packaged with ritonavir) is a strong inhibitor of CYP3A, and an inhibitor of CYP2D6, P-gp and OATP1B1. (Nirmatrelvir and ritonavir label, Drug interactions)

Cimetidine Cimetidine has demonstrated interference with the elimination of some quinolones. (Ofloxacin label, Drug interactions)

Some examples of such drugs are erythromycin, itraconazole, ketoconazole, fluconazole, calcium channel blockers and cimetidine. (Pimecrolimus label, Drug interactions)

Effient can be administered with aspirin (75 mg to 325 mg per day), heparin, GPIIb/IIIa inhibitors, statins, digoxin, and drugs that elevate gastric pH, including proton pump inhibitors and H 2 blockers [see Clinical Pharmacology (12.3) ] . (Prasugrel label, Drug interactions)

Effects of Other Drugs on Ranolazine Strong CYP3A Inhibitors Concomitant use of ASPRUZYO Sprinkle with strong CYP3A inhibitors, including ketoconazole, itraconazole, clarithromycin, nefazodone, nelfinavir, ritonavir, indinavir, and saquinavir is contraindicated [see Contraindications (4), Clinical Pharmacology (12.3)]. (Ranolazine label, Drug interactions)

Clinically Significant Interactions Affecting Other Drugs CYP3A Substrates Where Small Concentration Changes May Lead to Serious Adverse Reactions Clinical Impact Ritlecitinib is a CYP3A inhibitor. (Ritlecitinib label, Drug interactions)

Strong Inhibitors of CYP2D6 The impact on the efficacy of tamoxifen with co-administration of strong CYP2D6 inhibitors (e.g., paroxetine) is not well established. (Tamoxifen label, Drug interactions)

Cimetidine and Ranitidine Cimetidine and ranitidine do not affect the clearance of valproate. (Valproic acid label, Drug interactions)

Cimetidine The interaction between cimetidine and chronically administered verapamil has not been studied. (Verapamil label, Drug interactions)

Long-term acid-reducing therapy interferes with B12 absorption from food and can lead to deficiency. (NIH Office of Dietary Supplements, Vitamin B12)

However, no formal drug-drug interaction studies between zileuton and CYP3A4 inhibitors, such as ketaconazole, have been conducted. (Zileuton label, Drug interactions)

Effects of Concomitant Acid Blockers or Antibiotics A population pharmacokinetic analysis suggests that the pharmacokinetics of alvimopan were not affected by concomitant administration of acid blockers (proton pump inhibitors (PPIs), histamine-2 (H 2 ) receptor antagonists) or antibiotics. (Alvimopan label, Drug interactions)

Pharmacokinetic studies document no clinically relevant interactions with other agents given concomitantly, including thiazide diuretics and cimetidine. (Bisoprolol label, Drug interactions)

Pharmacokinetic studies document no clinically relevant interactions with other agents given concomitantly, including thiazide diuretics and cimetidine. (Bisoprolol and hydrochlorothiazide label, Precautions)

Inhibitors of Cytochrome P450 3A4 In controlled clinical studies co-administration of desloratadine with ketoconazole, erythromycin, or azithromycin resulted in increased plasma concentrations of desloratadine and 3 hydroxydesloratadine, but there were no clinically relevant changes in the safety profile of desloratadine. [See Clinical Pharmacology (12.3) .]… (Desloratadine label, Drug interactions)

Cimetidine A pharmacokinetic interaction study with cimetidine (Study P004) showed no clinically significant effect on letrozole pharmacokinetics. (Letrozole label, Drug interactions)

Drug Interactions No clinically significant drug interactions have been found in studies of losartan potassium with hydrochlorothiazide, digoxin, warfarin, cimetidine and phenobarbital. (Losartan label, Drug interactions)

Effect of Other Drugs on Micafungin in Sodium Chloride Injection CYP3A4, CYP2C9 and CYP2C19 Inhibitors Co-administration of Micafungin in Sodium Chloride Injection with cyclosporine, itraconazole, voriconazole and fluconazole did not alter the pharmacokinetics of micafungin. (Micafungin label, Drug interactions)

…Clinically Significant Drug Interaction with TAMIFLU No dose adjustments are needed for either oseltamivir or the concomitant drug when coadministering oseltamivir with amoxicillin, acetaminophen, aspirin, cimetidine, antacids (magnesium and aluminum hydroxides and calcium carbonates), rimantadine, amantadine, or warfarin [see Clinical Pharmacology (12.3) ] . (Oseltamivir label, Drug interactions)

Other agents Drug interaction studies of quinapril hydrochloride with other agents showed: Multiple dose therapy with propranolol or cimetidine has no effect on the pharmacokinetics of single doses of quinapril hydrochloride. (Quinapril label, Drug interactions)

Interaction of Tiagabine HCl with Other Drugs: Cimetidine : Co-administration of cimetidine (800 mg/day) to patients taking tiagabine chronically had no effect on tiagabine pharmacokinetics. (Tiagabine label, Drug interactions)

Other No clinically significant pharmacokinetic interaction has been found between trandolaprilat and food, cimetidine, digoxin, or furosemide. (Trandolapril label, Drug interactions)

Other HIV Protease Inhibitors (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects of Indinavir on Voriconazole Exposure In Vitro Studies Demonstrated Potential for Inhibition of Voriconazole Metabolism (Increased Plasma Exposure) No dosage adjustment in the voriconazole dosage needed for concomitant administration with indinavir. (Voriconazole label, Drug interactions)