Phentermine and topiramate interactions

Phentermine and topiramate (Qsymia), a CNS stimulant has 299 documented interactions across the FDA labels and fact sheets we index: 117 major, 167 moderate, 14 minor, and 1 where a label reports no significant interaction. Each entry below quotes the sentence behind it. This drug page is a starting point, not a verdict for your situation.

Major interactions (117)

  • Acetazolamidecarbonic anhydrase inhibitorMajor

    Avoid use of phentermine and topiramate extended-release capsules with other carbonic anhydrase inhibitors. (Phentermine and topiramate label, Warnings and precautions)

  • Albuterolbeta-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • AlcoholAlcoholMajor

    Avoid excessive use of alcohol ( 7 ). (Phentermine and topiramate label, Drug interactions)

  • AlprazolambenzodiazepineMajor

    • Effects on Driving and Operating Machinery: Patients receiving • alprazolam XR should be cautioned against operating machinery or driving a motor vehicle, as well as avoiding concomitant use of alcohol and other central nervous system (CNS) depressant drugs. (Alprazolam label, Warnings and precautions)

  • Hypersensitivity reactions such as angioedema and anaphylactic reactions have been reported in patients treated with other amphetamine products [see Adverse Reactions ( 6.2 )] . taking monoamine oxidase inhibitors (MAOIs), or within 14 days of stopping MAOIs (including MAOIs such as linezolid or intravenous methylene blue), because of an increased risk of hypertensive… (Amphetamine and dextroamphetamine label, Contraindications)

  • ApixabananticoagulantMajor

    • Simultaneous use of combined P-gp and strong CYP3A4 inducers reduces blood levels of apixaban: Avoid concomitant use. (Apixaban label, Drug interactions)

  • ApremilastPDE4 inhibitorMajor

    Drug Interactions : Use with strong cytochrome P450 enzyme inducers (e.g., rifampin, phenobarbital, carbamazepine, phenytoin) is not recommended because loss of efficacy may occur ( 5.5 , 7.1 ) (Apremilast label, Warnings and precautions)

  • AripiprazoleantipsychoticMajor

    CYP3A4 Inducers : Avoid concomitant use for greater than 14 days ( 7.1 ) (Aripiprazole label, Drug interactions)

  • Bictegravir, emtricitabine, and tenofovir alafenamideantiretroviralMajor

    Concomitant administration of BIXLENVO is contraindicated with: dofetilide due to the potential for increased dofetilide plasma concentrations and associated serious and/or life-threatening events. strong CYP3A inducers due to decreased plasma concentrations of BIC and LEN, which may result in the loss of therapeutic effect and development of resistance to BIXLENVO. (Bictegravir, emtricitabine, and tenofovir alafenamide label, Contraindications)

  • Budesonide and formoterolcorticosteroidMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • BuprenorphineopioidMajor

    Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Buprenorphine label, Boxed warning)

  • BupropionantidepressantMajor

    Bupropion hydrochloride extended-release tablets (XL) are contraindicated in patients undergoing abrupt discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs [see Warnings and Precautions (5.3) and Drug Interactions (7.3)] . (Bupropion label, Contraindications)

  • ButorphanolopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Butorphanol label, Boxed warning)

  • CariprazineantipsychoticMajor

    Intervention: Concomitant use of VRAYLAR with a CYP3A4 inducer is not recommended [see Dosage and Administration ( 2.1 , 2.6 ) ] . (Cariprazine label, Drug interactions)

  • CetirizineantihistamineMajor

    Avoid concurrent use of QUZYTTIR with alcohol or other CNS depressants because additional reduction in alertness and additional impairment of CNS performance may occur. (Cetirizine label, Warnings and precautions)

  • CiprofloxacinfluoroquinoloneMajor

    Table 8: Drugs That are Affected by and Affecting Ciprofloxacin Drugs That are Affected by Ciprofloxacin Drug(s) Recommendation Comments Tizanidine Contraindicated Concomitant administration of tizanidine and ciprofloxacin is contraindicated due to the potentiation of hypotensive and sedative effects of tizanidine [see Contraindications ( 4.2 )]. (Ciprofloxacin label, Drug interactions)

  • CitalopramSSRIMajor

    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)

  • Clonidinealpha-adrenergic agonistMajor

    Avoid use with other central nervous system (CNS) depressants ( 5.3 ) (Clonidine label, Warnings and precautions)

  • Clopidogrelantiplatelet agentMajor

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

  • ClozapineantipsychoticMajor

    • Concomitant use of Strong CYP3A4 Inducers is not recommended. (Clozapine label, Drug interactions)

  • CodeineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Codeine label, Boxed warning)

  • Cyclobenzaprinemuscle relaxantMajor

    Based on its structural similarity to TCAs, concomitant use of TONMYA with: MAO inhibitors may be life-threatening [see Contraindications (4) ] , Alcohol, barbiturates, and other CNS depressants may increase the risk of adverse reactions associated with these drugs, Tramadol may increase the seizure risk, Guanethidine or other similar acting drugs may block the… (Cyclobenzaprine label, Drug interactions)

  • Daridorexantsedative-hypnoticMajor

    Moderate or Strong CYP3A4 inducers: Avoid concomitant use. (Daridorexant label, Drug interactions)

  • Diltiazemcalcium channel blockerMajor

    Coadministration of diltiazem with rifampin or any known CYP3A4 inducer should be avoided when possible, and alternative therapy considered [see Clinical Pharmacology (12.3)]. a Strong and moderate inhibitors increase the AUC of sensitive substrates of CYP3A4 by ≥ 5 and ≥ 2-fold, respectively b These examples are a guide and not considered a comprehensive list… (Diltiazem label, Drug interactions)

  • Divalproex (valproate)anticonvulsantMajor

    Children under the age of two years are at a considerably increased risk of developing fatal hepatotoxicity, especially those on multiple anticonvulsants, those with congenital metabolic disorders, those with severe seizure disorders accompanied by mental retardation, and those with organic brain disease. (Divalproex (valproate) label, Boxed warning)

  • Dorzolamidecarbonic anhydrase inhibitorMajor

    Avoid use of phentermine and topiramate extended-release capsules with other carbonic anhydrase inhibitors. (Phentermine and topiramate label, Warnings and precautions)

  • Dorzolamide and timololcarbonic anhydrase inhibitorMajor

    Avoid use of phentermine and topiramate extended-release capsules with other carbonic anhydrase inhibitors. (Phentermine and topiramate label, Warnings and precautions)

  • DronabinolcannabinoidMajor

    Avoid concomitant use of other drugs that are also associated with similar cardiac effects (e.g., amphetamines, other sympathomimetic agents, atropine, amoxapine, scopolamine, antihistamines, other anticholinergic agents, amitriptyline, desipramine, other tricyclic antidepressants). (Dronabinol label, Warnings and precautions)

  • DronedaroneantiarrhythmicMajor

    CYP3A inducers: Avoid concomitant use. (Dronedarone label, Drug interactions)

  • DroxidopasympathomimeticMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • Elexacaftor, tezacaftor, and ivacaftorMajor

    Therefore, concomitant use with strong CYP3A inducers is not recommended [see Drug Interactions (7.1) and Clinical Pharmacology (12.3) ] . (Elexacaftor, tezacaftor, and ivacaftor label, Warnings and precautions)

  • Empagliflozin and metforminSGLT2 inhibitorMajor

    Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, hepatic… (Empagliflozin and metformin label, Boxed warning)

  • EpinephrinesympathomimeticMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • Eszopiclonesedative-hypnoticMajor

    The use of LUNESTA with other sedative-hypnotics at bedtime or the middle of the night is not recommended. (Eszopiclone label, Warnings and precautions)

  • FelbamateanticonvulsantMajor

    IT IS NOT KNOWN WHETHER CONCOMITANT USE OF OTHER ANTIEPILEPTIC DRUGS AND/OR OTHER DRUGS AFFECT THE INCIDENCE OF HEPATIC FAILURE. (Felbamate label, Boxed warning)

  • FentanylopioidMajor

    • Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Fentanyl label, Boxed warning)

  • FlibanserinCNS depressantMajor

    Preventing or Managing DI The concomitant use of ADDYI with CYP3A4 inducers is not recommended. (Flibanserin label, Drug interactions)

  • Fluticasone and salmeterolcorticosteroidMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • Formoterolbeta-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • Glyburide and metforminsulfonylureaMajor

    Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g. , acute congestive heart failure), excessive alcohol intake, hepatic… (Glyburide and metformin label, Boxed warning)

  • HaloperidolantipsychoticMajor

    Seizures: HALDOL DECANOATE is generally not recommended in patients receiving antiseizure drugs or who have a history of seizures or EEG abnormalities. (Haloperidol label, Warnings and precautions)

  • Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Hydrocodone and acetaminophen label, Boxed warning)

  • HydromorphoneopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death . (Hydromorphone label, Boxed warning)

  • HydroxyzineantihistamineMajor

    Rarely, cardiac arrests and death have been reported in association with the combined use of hydroxyzine hydrochloride intramuscularly and other CNS depressants. (Hydroxyzine label, Precautions)

  • IsoniazidantibioticMajor

    …Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release… (Phentermine and topiramate label, Contraindications)

  • Itraconazoleazole antifungalMajor

    Anticonvulsants Carbamazepine Not recommended 2 weeks before, during, and 2 weeks after TOLSURA treatment. (Itraconazole label, Drug interactions)

  • IvabradineMajor

    Avoid concomitant use of CYP3A4 inducers when using Corlanor. (Ivabradine label, Drug interactions)

  • KetamineCNS depressantMajor

    Benzodiazepines, Opioid Analgesics, or other CNS Depressants : Concomitant use may result in profound sedation, respiratory depression, coma, or death. (Ketamine label, Drug interactions)

  • Ketoconazoleazole antifungalMajor

    This may potentiate and prolong hypnotic and sedative effects, especially with repeated dosing or chronic administration of these agents. (Ketoconazole label, Contraindications)

  • Lemborexantsedative-hypnoticMajor

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

  • Levalbuterolbeta-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • LevocetirizineantihistamineMajor

    Avoid concurrent use of alcohol or other central nervous system depressants with XYZAL. (Levocetirizine label, Warnings and precautions)

  • LevorphanolopioidMajor

    Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Levorphanol label, Boxed warning)

  • LinezolidantibioticMajor

    …Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release… (Phentermine and topiramate label, Contraindications)

  • Liothyroninethyroid hormoneMajor

    • Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects [see Adverse Reactions (6) , Drug Interactions (7.7) , and Overdosage (10) ] . (Liothyronine label, Boxed warning)

  • LorazepambenzodiazepineMajor

    Caution patients receiving LOREEV XR against operating machinery or driving a motor vehicle as well to avoid the concomitant use of alcohol and other CNS depressant drugs during treatment ( 5.4 , 7 ) (Lorazepam label, Warnings and precautions)

  • LumateperoneantipsychoticMajor

    CYP3A4 inducers: Avoid concomitant use with CAPLYTA. (Lumateperone label, Drug interactions)

  • LurasidoneantipsychoticMajor

    Strong CYP3A4 inducers (e.g., rifampin, avasimibe, St. (Lurasidone label, Contraindications)

  • MacitentanMajor

    Strong CYP3A4 inducers (rifampin) reduce exposure to macitentan: avoid co-administration with OPSUMIT ( 7.1 , 12.3 ). (Macitentan label, Drug interactions)

  • MeperidineopioidMajor

    Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Meperidine label, Boxed warning)

  • MetforminbiguanideMajor

    Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, and hepatic… (Metformin label, Boxed warning)

  • MethadoneopioidMajor

    Managing Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, is a risk factor for respiratory depression and death [see Warnings and Precautions ( 5.2 )]. (Methadone label, Boxed warning)

  • MidazolambenzodiazepineMajor

    WARNING: PERSONNEL AND EQUIPMENT FOR MONITORING AND RESUSCITATION, AND RISKS FROM CONCOMITANT USE WITH OPIOID ANALGESICS AND OTHER SEDATIVE-HYPNOTICS Personnel and Equipment for Monitoring and ResuscitationOnly personnel trained in the administration of procedural sedation, and not involved in the conduct of the diagnostic or therapeutic procedure, should administer… (Midazolam label, Boxed warning)

  • Midodrinealpha-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • Mirabegronbeta-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • ModafinilCNS stimulantMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • MorphineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Morphine label, Boxed warning)

  • NalbuphineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Nalbuphine label, Boxed warning)

  • Naldemedineopioid antagonistMajor

    John's Wort) Clinical Impact Significant decrease in plasma naldemedine concentrations, which may reduce efficacy [see Clinical Pharmacology (12.3) ] Intervention Avoid use of SYMPROIC with strong CYP3A inducers. (Naldemedine label, Drug interactions)

  • Naltrexone and bupropionopioid antagonistMajor

    …(e.g., buprenorphine) use, or acute opiate withdrawal [see Warnings and Precautions (5.4) and Drug Interactions (7.2) ] Patients undergoing an abrupt discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs [see Warnings and Precautions (5.3) and Drug Interactions (7.7) ] Concomitant administration of monoamine oxidase inhibitors (MAOI). (Naltrexone and bupropion label, Contraindications)

  • Nifedipinedihydropyridine calcium channel blockerMajor

    Avoid co-administration of nifedipine with phenytoin or any known CYP3A4 inducer or consider an alternative antihypertensive therapy. (Nifedipine label, Drug interactions)

  • Nirmatrelvir and ritonavirantiviralMajor

    …contraindicated with drugs that are primarily metabolized by CYP3A and for which elevated concentrations are associated with serious and/or life-threatening reactions and drugs that are strong CYP3A inducers where significantly reduced nirmatrelvir or ritonavir plasma concentrations may be associated with the potential for loss of virologic response and possible resistance. (Nirmatrelvir and ritonavir label, Contraindications)

  • Counsel patients to use a back-up method or alternative method of contraception when enzyme inducers are used with COCs ( 7.1 ) -- - ---------- ------ USE IN SPECIFIC POPULATIONS---- -- -- --------- ---- Lactation: Not recommended; Lo Loestrin Fe can decrease milk production ( 8.2 ) (Norethindrone and ethinyl estradiol label, Drug interactions)

  • OliceridineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Oliceridine label, Boxed warning)

  • OlopatadineantihistamineMajor

    Avoid concurrent use of alcohol or other central nervous system depressants with olopatadine hydrochloride nasal spray ( 5.2 ). (Olopatadine label, Warnings and precautions)

  • OxycodoneopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Oxycodone label, Boxed warning)

  • …LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; NEONATAL OPIOID WITHDRAWAL SYNDROME; CYTOCHROME P450 3A4 INTERACTION; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Addiction, Abuse, and Misuse Oxycodone hydrochloride tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to… (Oxycodone and acetaminophen label, Boxed warning)

  • OxymorphoneopioidMajor

    Risks From Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Oxymorphone label, Boxed warning)

  • PalbociclibCYP3A4 inhibitorMajor

    CYP3A Inducers: Avoid concurrent use of IBRANCE with strong CYP3A inducers. (Palbociclib label, Drug interactions)

  • PaliperidoneantipsychoticMajor

    Strong CYP3A4 and P-glycoprotein (P-gp) inducers : Avoid using a strong inducer of CYP3A4 and/or P-gp during a dosing interval for ERZOFRI. (Paliperidone label, Drug interactions)

  • Pentazocine and naloxoneopioidMajor

    …MITIGATION STRATEGY (REMS); LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; NEONATAL OPIOID WITHDRAWAL SYNDROME; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Addiction, Abuse, and Misuse Pentazocine and Naloxone Tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to… (Pentazocine and naloxone label, Boxed warning)

  • PhenelzineMAO inhibitorMajor

    …Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release… (Phentermine and topiramate label, Contraindications)

  • PhentermineCNS stimulantMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • PhenylephrinedecongestantMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • PimavanserinantipsychoticMajor

    Strong or Moderate CYP3A4 Inducers: Avoid concomitant use of NUPLAZID. (Pimavanserin label, Drug interactions)

  • Pioglitazone and metforminthiazolidinedioneMajor

    Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, hepatic… (Pioglitazone and metformin label, Boxed warning)

  • PseudoephedrinedecongestantMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • RanolazineQT-prolonging drugMajor

    ASPRUZYO Sprinkle is contraindicated in patients: Taking strong inhibitors of CYP3A [see Drug Interactions (7.1)] Taking inducers of CYP3A [see Drug Interactions (7.1)] With liver cirrhosis [see Use in Specific Populations (8.6)] Strong CYP3A inhibitors (e.g., ketoconazole, clarithromycin, nelfinavir) (4, 7.1) (Ranolazine label, Contraindications)

  • RasagilineMAO inhibitorMajor

    …Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release… (Phentermine and topiramate label, Contraindications)

  • RimegepantMajor

    • Strong and Moderate CYP3A Inducers: Avoid concomitant administration. (Rimegepant label, Drug interactions)

  • RitonavirantiretroviralMajor

    WARNING: DRUG-DRUG INTERACTIONS LEADING TO POTENTIALLY SERIOUS AND/OR LIFE THREATENING REACTIONS Co-administration of NORVIR with several classes of drugs including sedative hypnotics, antiarrhythmics, or ergot alkaloid preparations may result in potentially serious and/or life-threatening adverse events due to possible effects of NORVIR on the hepatic metabolism… (Ritonavir label, Boxed warning)

  • RivaroxabananticoagulantMajor

    Avoid concomitant use of XARELTO with drugs that are known combined P-gp and strong CYP3A inducers [see Drug Interactions (7.3) ] . (Rivaroxaban label, Warnings and precautions)

  • RoflumilastPDE4 inhibitorMajor

    • Drug Interactions: Use with strong cytochrome P450 enzyme inducers (e.g., rifampicin, phenobarbital, carbamazepine, phenytoin) is not recommended. (Roflumilast label, Warnings and precautions)

  • Salmeterolbeta-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • SelegilineMAO inhibitorMajor

    …Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release… (Phentermine and topiramate label, Contraindications)

  • SirolimusimmunosuppressantMajor

    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)

  • Sitagliptin and metforminDPP-4 inhibitorMajor

    Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, hepatic… (Sitagliptin and metformin label, Boxed warning)

  • Sodium oxybateCNS depressantMajor

    Many patients who received Xyrem during clinical trials in narcolepsy were receiving central nervous system stimulants [see Clinical Trials ( 14 )]. (Sodium oxybate label, Boxed warning)

  • Sofosbuvir and velpatasvirantiviralMajor

    Anticonvulsants: carbamazepine phenytoin phenobarbital ↓ sofosbuvir ↓ velpatasvir ↓ voxilaprevir Coadministration is not recommended. (Sofosbuvir and velpatasvir label, Drug interactions)

  • Tamoxifenselective estrogen receptor modulatorMajor

    Inducers of CYP3A4 Strong CYP3A4 inducers should not be used with tamoxifen. (Tamoxifen label, Drug interactions)

  • TapentadolopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Tapentadol label, Boxed warning)

  • Tasimelteonsedative-hypnoticMajor

    Strong CYP3A4 inducers (e.g., rifampin): Avoid use of HETLIOZ in combination with rifampin or other CYP3A4 inducers, because of decreased exposure ( 7.2 , 12.3 ) (Tasimelteon label, Drug interactions)

  • Terbutalinebeta-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • Ticagrelorantiplatelet agentMajor

    • Avoid use with strong CYP3A inhibitors or CYP3A inducers. (Ticagrelor label, Drug interactions)

  • TramadolopioidMajor

    Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Tramadol label, Boxed warning)

  • TranylcypromineMAO inhibitorMajor

    …Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release… (Phentermine and topiramate label, Contraindications)

  • TretinoinretinoidMajor

    Avoid concomitant use with strong CYP3A inducers if possible. (Tretinoin label, Drug interactions)

  • TriazolambenzodiazepineMajor

    • Effects on Driving and Operating Heavy Machinery : Patients receiving triazolam should be cautioned against driving or operating heavy machinery, as well as avoiding concomitant use with alcohol and other CNS depressant drugs. (Triazolam label, Warnings and precautions)

  • UbrogepantMajor

    Strong CYP3A4 Inducers: Should be avoided as concomitant use will result in reduction of ubrogepant exposure. (Ubrogepant label, Drug interactions)

  • Umeclidinium and vilanterolanticholinergicMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • UpadacitinibimmunosuppressantMajor

    Strong CYP3A4 Inducers : Coadministration of RINVOQ/RINVOQ LQ with strong CYP3A4 inducers is not recommended. (Upadacitinib label, Drug interactions)

  • ValbenazineVMAT2 inhibitorMajor

    Use of strong CYP3A4 inducers with INGREZZA or INGREZZA SPRINKLE Concomitant use is not recommended. (Valbenazine label, Drug interactions)

  • Valproic acidanticonvulsantMajor

    Children under the age of two years are at a considerably increased risk of developing fatal hepatotoxicity, especially those on multiple anticonvulsants, those with congenital metabolic disorders, those with severe seizure disorders accompanied by mental retardation, and those with organic brain disease. (Valproic acid label, Boxed warning)

  • Vibegronbeta-adrenergic agonistMajor

    …(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines. (Phentermine and topiramate label, Contraindications)

  • Zaleplonsedative-hypnoticMajor

    The use of zaleplon with other sedative-hypnotics at bedtime or the middle of the night is not recommended (see ). (Zaleplon label, Warnings)

  • Zolpidemsedative-hypnoticMajor

    The use of Zolpidem Tartrate with other sedative-hypnotics (including other zolpidem products) at bedtime or the middle of the night is not recommended. (Zolpidem label, Warnings and precautions)

  • ZonisamideanticonvulsantMajor

    Avoid use of phentermine and topiramate extended-release capsules with other carbonic anhydrase inhibitors. (Phentermine and topiramate label, Warnings and precautions)

Moderate interactions (167)

  • AclidiniumanticholinergicModerate

    Sympathomimetics, Methylxanthines, Steroids In clinical studies, concurrent administration of aclidinium bromide and other drugs commonly used in the treatment of COPD including sympathomimetics (short-acting beta 2 agonists), methylxanthines, and oral and inhaled steroids showed no increases in adverse drug reactions. (Aclidinium label, Drug interactions)

  • AlbendazoleModerate

    Risk of Neurologic Symptoms: Neurocysticercosis patients may experience cerebral hypertensive episodes, seizures or focal neurologic deficits after initiation of therapy; begin appropriate steroid and anticonvulsant therapy. (Albendazole label, Warnings and precautions)

  • Allopurinolxanthine oxidase inhibitorModerate

    Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

  • Amiloridepotassium-sparing diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • Amitriptylinetricyclic antidepressantModerate

    Amitriptyline Clinical Impact Some patients may experience a large increase in amitriptyline concentration in the presence of topiramate. (Phentermine and topiramate label, Drug interactions)

  • Amlodipinedihydropyridine calcium channel blockerModerate

    Blood pressure should be closely monitored when amlodipine is co-administered with CYP3A inducers. (Amlodipine label, Drug interactions)

  • Amlodipine and benazeprildihydropyridine calcium channel blockerModerate

    Blood pressure should be monitored when amlodipine is coadministered with CYP3A4 inducers (e.g. rifampicin, St. (Amlodipine and benazepril label, Drug interactions)

  • AsenapineantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Aspirin and dipyridamoleantiplatelet agentModerate

    Anticonvulsants Salicylic acid can displace protein-bound phenytoin and valproic acid, leading to a decrease in the total concentration of phenytoin and an increase in serum valproic acid levels. (Aspirin and dipyridamole label, Drug interactions)

  • Baclofenmuscle relaxantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Bisoprolol and hydrochlorothiazidebeta blockerModerate

    Concomitant administration of hydrochlorothiazide alone with topiramate alone has been shown to increase the C max and AUC of topiramate by 27% and 29%, respectively. (Phentermine and topiramate label, Drug interactions)

  • BrexpiprazoleantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Brimonidinealpha-adrenergic agonistModerate

    Use with CNS depressants may result in an additive or potentiating effect. (Brimonidine label, Drug interactions)

  • BudesonidecorticosteroidModerate

    Patients with major risk factors for decreased bone mineral content, such as prolonged immobilization, family history of osteoporosis, post menopausal status, tobacco use, advance age, poor nutrition, or chronic use of drugs that can reduce bone mass (e.g., anticonvulsants, oral corticosteroids) should be monitored and treated with established standards of care. (Budesonide label, Warnings and precautions)

  • Bumetanideloop diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • Buprenorphine and naloxoneopioidModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Buspironeserotonergic drugModerate

    Triazolam/flurazepam: Coadministration of buspirone with either triazolam or flurazepam did not appear to prolong or intensify the sedative effects of either benzodiazepine. (Buspirone label, Drug interactions)

  • Butalbital, acetaminophen, and caffeinebarbiturateModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • CalciumVitamin and mineralModerate

    Increased ratio of urinary calcium/citrate increases the risk of kidney stones and/or nephrocalcinosis. (Phentermine and topiramate label, Warnings and precautions)

  • CanagliflozinSGLT2 inhibitorModerate

    Table 7: Clinically Significant Drug Interactions with INVOKANA UGT Enzyme Inducers Clinical Impact: UGT enzyme inducers decrease canagliflozin exposure which may reduce the effectiveness of INVOKANA. (Canagliflozin label, Drug interactions)

  • Cannabidiol (prescription)anticonvulsantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • CarbamazepineanticonvulsantModerate

    Antiepileptic Drugs Clinical Impact Concomitant administration of phenytoin or carbamazepine with topiramate in patients with epilepsy, decreased plasma concentrations of topiramate by 48% and 40%, respectively, when compared to topiramate given alone [see Clinical Pharmacology (12.3) ] . (Phentermine and topiramate label, Drug interactions)

  • Carisoprodolmuscle relaxantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • CenobamateanticonvulsantModerate

    Concomitant use with other CNS depressants or alcohol may have additive effects. (Cenobamate label, Warnings and precautions)

  • ChlordiazepoxidebenzodiazepineModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • ChlorpromazineantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Chlorthalidonethiazide diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • Cilostazolantiplatelet agentModerate

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

  • Clarithromycinmacrolide antibioticModerate

    Antiepileptics: Carbamazepine Use With Caution Carbamazepine: Concomitant administration of single doses of clarithromycin and carbamazepine has been shown to result in increased plasma concentrations of carbamazepine. (Clarithromycin label, Drug interactions)

  • ClindamycinantibioticModerate

    Inducers of CYP3A4 and CYP3A5 Inducers of CYP3A4 and/or CYP3A5 may reduce plasma concentrations of clindamycin. (Clindamycin label, Drug interactions)

  • ClobazambenzodiazepineModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • ClonazepambenzodiazepineModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Conjugated estrogensestrogenModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • CyclosporineimmunosuppressantModerate

    Drugs/Dietary Supplements That Decrease Cyclosporine Concentrations Antibiotics Anticonvulsants Other Drugs/Dietary Supplements nafcillin carbamazepine bosentan St. (Cyclosporine label, Drug interactions)

  • Dantrolenemuscle relaxantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • DesvenlafaxineSNRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St. (Desvenlafaxine label, Warnings and precautions)

  • DeutetrabenazineVMAT2 inhibitorModerate

    Alcohol or other sedating drugs: May have additive sedation and somnolence ( 7.5 ) (Deutetrabenazine label, Drug interactions)

  • Dexlansoprazoleproton pump inhibitorModerate

    Clinically Relevant Interactions Affecting DEXILANT When Coadministered with Other Drugs and Substances CYP2C19 or CYP3A4 Inducers Clinical Impact: Decreased exposure of dexlansoprazole when used concomitantly with strong inducers [see Clinical Pharmacology (12.3) ] . (Dexlansoprazole label, Drug interactions)

  • DiazepambenzodiazepineModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • DiclofenacNSAIDModerate

    Exercise caution when prescribing Diclofenac Potassium with concomitant drugs that are known to be potentially hepatotoxic (e.g., acetaminophen, antibiotics, antiepileptics). (Diclofenac label, Warnings and precautions)

  • DicyclomineanticholinergicModerate

    …drugs including dicyclomine hydrochloride: amantadine, antiarrhythmic agents of Class I (e.g., quinidine), antihistamines, antipsychotic agents (e.g., phenothiazines), benzodiazepines, MAO inhibitors, narcotic analgesics (e.g., meperidine), nitrates and nitrites, sympathomimetic agents, tricyclic antidepressants, and other drugs having anticholinergic activity. (Dicyclomine label, Drug interactions)

  • Digoxindigitalis glycosideModerate

    Sympathomimetics Epinephrine Can increase the risk of cardiac arrhythmias. (Digoxin label, Drug interactions)

  • DimenhydrinateantihistamineModerate

    The concomitant use of alcohol or other central nervous system depressants may have an additive effect. (Dimenhydrinate label, Warnings)

  • DiphenhydramineantihistamineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • DofetilideantiarrhythmicModerate

    Concomitant medications were grouped as ACE inhibitors, oral anticoagulants, calcium channel blockers, beta blockers, cardiac glycosides, inducers of CYP3A4, substrates and inhibitors of CYP3A4, substrates and inhibitors of P-glycoprotein, nitrates, sulphonylureas, loop diuretics, potassium sparing diuretics, thiazide diuretics, substrates and inhibitors of tubular… (Dofetilide label, Drug interactions)

  • Doxepintricyclic antidepressantModerate

    Although behaviors such as "sleep-driving" may occur with hypnotics alone at therapeutic doses, the use of alcohol and other CNS depressants with hypnotics appears to increase the risk of such behaviors, as does the use of hypnotics at doses exceeding the maximum recommended dose. (Doxepin label, Warnings and precautions)

  • Doxycyclinetetracycline antibioticModerate

    Barbiturates and Anti-Epileptics Barbiturates, carbamazepine, and phenytoin decrease the half-life of doxycycline. (Doxycycline label, Drug interactions)

  • Drospirenone and ethinyl estradioloral contraceptiveModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • DuloxetineSNRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St. (Duloxetine label, Warnings and precautions)

  • EluxadolineopioidModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Emtricitabine and tenofovirantiretroviralModerate

    Other Agents Anticonvulsants: carbamazepine oxcarbazepine phenobarbital phenytoin ↓ TAF Consider alternative anticonvulsant. (Emtricitabine and tenofovir label, Drug interactions)

  • Eplerenonealdosterone antagonistModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • EscitalopramSSRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, meperidine, methadone, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. (Escitalopram label, Warnings and precautions)

  • EslicarbazepineanticonvulsantModerate

    Anyone considering prescribing APTIOM or any other AED must balance this risk with the risk of untreated illness. (Eslicarbazepine label, Warnings and precautions)

  • Esmololbeta blockerModerate

    Sympathomimetic drugs: Dose adjustment needed ( 7 ) (Esmolol label, Drug interactions)

  • Esomeprazoleproton pump inhibitorModerate

    Table 4: Clinically Relevant Interactions Affecting Esomeprazole When Co-Administered with Other Drugs CYP2C19 or CYP3A4 Inducers Clinical Impact: Decreased exposure of esomeprazole when used concomitantly with strong inducers [see Clinical Pharmacology (12.3) ]. (Esomeprazole label, Drug interactions)

  • EstradiolestrogenModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • Ethacrynic acidloop diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • EverolimusimmunosuppressantModerate

    Interaction With Strong Inhibitors and Inducers of CYP3A4 Coadministration of Zortress with strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, voriconazole, clarithromycin, telithromycin, ritonavir, boceprevir, telaprevir) or strong CYP3A4 inducers (e.g., rifampin, rifabutin) is not recommended without close monitoring of everolimus whole blood trough… (Everolimus label, Warnings and precautions)

  • Felodipinedihydropyridine calcium channel blockerModerate

    Anticonvulsants - In a pharmacokinetic study, maximum plasma concentrations of felodipine were considerably lower in epileptic patients on long-term anticonvulsant therapy (e.g., phenytoin, carbamazepine, or phenobarbital) than in healthy volunteers. (Felodipine label, Drug interactions)

  • FesoterodineanticholinergicModerate

    CYP3A4 Inducers No dosing adjustments are recommended in the presence of CYP3A4 inducers, such as rifampin and carbamazepine. (Fesoterodine label, Drug interactions)

  • FlecainideantiarrhythmicModerate

    Limited data in patients receiving known enzyme inducers ( phenytoin, phenobarbital, carbamazepine ) indicate only a 30% increase in the rate of flecainide elimination. (Flecainide label, Drug interactions)

  • FluoxetineSSRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, meperidine, methadone, buspirone, amphetamines, and St. (Fluoxetine label, Warnings and precautions)

  • FluticasonecorticosteroidModerate

    Patients with major risk factors for decreased bone mineral content, such as prolonged immobilization, family history of osteoporosis, postmenopausal status, tobacco use, advanced age, poor nutrition, or chronic use of drugs that can reduce bone mass (e.g., anticonvulsants, oral corticosteroids), should be monitored and treated with established standards of care. (Fluticasone label, Warnings and precautions)

  • FluvoxamineSSRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, meperidine, methadone, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. (Fluvoxamine label, Warnings and precautions)

  • Furosemideloop diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • GabapentinanticonvulsantModerate

    When the decision is made to co-prescribe NEURONTIN with another CNS depressant, particularly an opioid, or to prescribe NEURONTIN to patients with underlying respiratory impairment, monitor patients for symptoms of respiratory depression and sedation, and consider initiating NEURONTIN at a low dose. (Gabapentin label, Warnings and precautions)

  • GlimepiridesulfonylureaModerate

    …somatropin, protease inhibitors, atypical antipsychotic medications (e.g., olanzapine and clozapine), barbiturates, diazoxide, laxatives, rifampin, thiazides and other diuretics, corticosteroids, phenothiazines, thyroid hormones, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics (e.g., epinephrine, albuterol, terbutaline), and isoniazid. (Glimepiride label, Drug interactions)

  • GlipizidesulfonylureaModerate

    …olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), thyroid hormones, phenytoin, nicotinic acid, and calcium channel blocking drugs. (Glipizide label, Drug interactions)

  • GlycopyrrolateanticholinergicModerate

    Other Anticholinergic Drugs There is potential for an additive interaction between glycopyrrolate and concomitantly used anticholinergic drugs (e.g., tricyclic antidepressants, anti-epileptics, class I antiarrhythmics, anti­-spasmodics, amantadine) resulting in increased anticholinergic adverse reactions. (Glycopyrrolate label, Drug interactions)

  • Guanfacinealpha-adrenergic agonistModerate

    In these cases, high-dosage guanfacine was discontinued; concomitant stimulant use was also reported, which may potentially increase hypertensive response upon abrupt discontinuation of guanfacine. (Guanfacine label, Warnings and precautions)

  • Hydrochlorothiazidethiazide diureticModerate

    Concomitant administration of hydrochlorothiazide alone with topiramate alone has been shown to increase the C max and AUC of topiramate by 27% and 29%, respectively. (Phentermine and topiramate label, Drug interactions)

  • HydrocortisonecorticosteroidModerate

    Concomitant administration of inducers of CYP3A4 may lead to decreases in serum concentrations of ALKINDI SPRINKLE and increase the risk of adverse reactions, including adrenal crisis. (Hydrocortisone label, Drug interactions)

  • IloperidoneantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • ImatinibCYP3A4 inhibitorModerate

    CYP3A4 inducers may decrease Gleevec C max and area under curve (AUC). (Imatinib label, Drug interactions)

  • Indapamidethiazide diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • Insulin aspartinsulinModerate

    …Insulin Aspart Drugs: Atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones. (Insulin aspart label, Drug interactions)

  • Insulin degludecinsulinModerate

    …Insulin Degludec Drugs: Atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones. (Insulin degludec label, Drug interactions)

  • Insulin detemirinsulinModerate

    …Effect of LEVEMIR Drugs: Atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones. (Insulin detemir label, Drug interactions)

  • Insulin glargineinsulinModerate

    …Glargine-yfgn Drugs: Atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones. (Insulin glargine label, Drug interactions)

  • Insulin lisproinsulinModerate

    …Effect of LYUMJEV Drugs: Atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), and thyroid hormones. (Insulin lispro label, Drug interactions)

  • IvacaftorCYP3A4 inhibitorModerate

    Concomitant Use with CYP3A Inducers Use of KALYDECO with strong CYP3A inducers, such as rifampin, substantially decreases the exposure of ivacaftor, which may reduce the therapeutic effectiveness of KALYDECO. (Ivacaftor label, Warnings and precautions)

  • LacosamideanticonvulsantModerate

    Anyone considering prescribing VIMPAT or any other AED must balance this risk with the risk of untreated illness. (Lacosamide label, Warnings and precautions)

  • LamotrigineanticonvulsantModerate

    Patients with History of Allergy or Rash to Other Antiepileptic Drugs The risk of rash may be increased in patients with a history of allergy or rash to other AEDs. (Lamotrigine label, Warnings and precautions)

  • Lansoprazoleproton pump inhibitorModerate

    Clinically Relevant Interactions Affecting PREVACID or PREVACID SoluTab When Coadministered with Other Drugs CYP2C19 OR CYP3A4 Inducers Clinical Impact: Decreased exposure of lansoprazole when used concomitantly with strong inducers [see Clinical Pharmacology (12.3) ] . (Lansoprazole label, Drug interactions)

  • LevomilnacipranSNRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St. (Levomilnacipran label, Warnings and precautions)

  • LevonorgestrelprogestinModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • Levonorgestrel and ethinyl estradioloral contraceptiveModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • Levothyroxinethyroid hormoneModerate

    Sympathomimetics Concurrent use may of sympathomimetics and levothyroxine may increase the effects of sympathomimetics or thyroid hormone. (Levothyroxine label, Drug interactions)

  • Lidocaine and prilocainelocal anestheticModerate

    …prilocaine, procaine, ropivacaine, tetracaine Antineoplastic agents cyclophosphamide, flutamide, hydroxyurea, isofamide, rasburicase Antibiotics dapsone, nitrofurantoin, para-aminosalicylic acid, sufonamides Antimalarials chloroquine, primaquine Anticonvulsants Phenobarbital, phenytoin, sodium valproate Other drugs acetaminophen, metoclopramide, quinine, sulfasalazine (Lidocaine and prilocaine label, Drug interactions)

  • LinagliptinDPP-4 inhibitorModerate

    Strong P-glycoprotein/CYP3A4 inducer: The efficacy of TRADJENTA may be reduced when administered in combination (e.g., with rifampin). (Linagliptin label, Drug interactions)

  • LisdexamfetamineCNS stimulantModerate

    Additionally, in studies of another stimulant, there was slowing of the increase in height [see Adverse Reactions (6.1) ] . (Lisdexamfetamine label, Warnings and precautions)

  • Lisinopril and hydrochlorothiazideACE inhibitorModerate

    Concomitant administration of hydrochlorothiazide alone with topiramate alone has been shown to increase the C max and AUC of topiramate by 27% and 29%, respectively. (Phentermine and topiramate label, Drug interactions)

  • Lofexidinealpha-adrenergic agonistModerate

    Increased Risk of CNS Depression with Concomitant use of CNS Depressant Drugs : Lofexidine tablets potentiates the CNS depressant effects of benzodiazepines and may potentiate the CNS depressant effects of alcohol, barbiturates, and other sedating drugs. (Lofexidine label, Warnings and precautions)

  • Losartan and hydrochlorothiazideangiotensin II receptor blocker (ARB)Moderate

    Concomitant administration of hydrochlorothiazide alone with topiramate alone has been shown to increase the C max and AUC of topiramate by 27% and 29%, respectively. (Phentermine and topiramate label, Drug interactions)

  • MeclizineantihistamineModerate

    • Coadministration of meclizine hydrochloride with other CNS depressants, including alcohol, may result in increased CNS depression ( 7.1 ). (Meclizine label, Drug interactions)

  • MedroxyprogesteroneprogestinModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • MegestrolprogestinModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • Methocarbamolmuscle relaxantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • MethylprednisolonecorticosteroidModerate

    Hepatic Enzyme Inducers (e.g., barbiturates, phenytoin, carbamazepine, rifampin) : Drugs which induce cytochrome P450 3A4 enzyme activity may enhance the metabolism of corticosteroids and require that the dosage of the corticosteroid be increased. (Methylprednisolone label, Drug interactions)

  • Metolazonethiazide diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • MirtazapineantidepressantModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. (Mirtazapine label, Warnings and precautions)

  • MometasonecorticosteroidModerate

    Patients with major risk factors for decreased bone mineral content, such as prolonged immobilization, family history of osteoporosis, or chronic use of drugs that can reduce bone mass (e.g., anticonvulsants and corticosteroids) should be monitored and treated with established standards of care. (Mometasone label, Warnings and precautions)

  • Naloxoneopioid antagonistModerate

    WARNINGS AND PRECAUTIONS Risk of Recurrent Respiratory and CNS Depression : Due to the duration of action of naloxone relative to the opioid, respiratory and CNS depression may recur after the first dose of naloxone. (Naloxone label, Warnings and precautions)

  • NintedanibModerate

    Coadministration with oral doses of a P-gp and CYP3A4 inducer, rifampicin, decreased exposure to nintedanib by 50%. (Nintedanib label, Drug interactions)

  • NorethindroneprogestinModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • Norgestimate and ethinyl estradioloral contraceptiveModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • Nortriptylinetricyclic antidepressantModerate

    Close supervision and careful adjustment of the dosage are required when Pamelor is used with other anticholinergic drugs and sympathomimetic drugs. (Nortriptyline label, Drug interactions)

  • OlanzapineantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Omeprazoleproton pump inhibitorModerate

    Table 4: Clinically Relevant Interactions Affecting Omeprazole When Co-Administered with Other Drugs CYP2C19 or CYP3A4 Inducers Clinical Impact: Decreased exposure of omeprazole when used concomitantly with strong inducers [see Clinical Pharmacology ( 12.3 )] . (Omeprazole label, Drug interactions)

  • OndansetronQT-prolonging drugModerate

    Phenytoin, Carbamazepine, and Rifampin In patients treated with potent inducers of CYP3A4 (i.e., phenytoin, carbamazepine, and rifampin), the clearance of ondansetron was significantly increased and ondansetron blood concentrations were decreased. (Ondansetron label, Drug interactions)

  • OrlistatModerate

    Drug Interactions and Decreased Vitamin Absorption ORLISTAT may interact with concomitant drugs including cyclosporine, levothyroxine, warfarin, amiodarone, antiepileptic drugs, and antiretroviral drugs [see Drug Interactions (7) ]. (Orlistat label, Warnings and precautions)

  • OxcarbazepineanticonvulsantModerate

    Therefore, if a patient develops a skin reaction while taking TRILEPTAL, consideration should be given to discontinuing TRILEPTAL use and prescribing another antiepileptic medication. (Oxcarbazepine label, Warnings and precautions)

  • ParoxetineSSRIModerate

    The risk is increased with concomitant use of other serotonergic agents (including triptans, tricyclic antidepressants, fentanyl, tramadol, meperidine, methadone, lithium, tryptophan, buspirone, amphetamines, and St. (Paroxetine label, Warnings and precautions)

  • PerampanelanticonvulsantModerate

    Patients should be carefully observed for signs of central nervous system (CNS) depression, such as somnolence and sedation, when FYCOMPA is used with other drugs with sedative properties because of potential additive effects. (Perampanel label, Warnings and precautions)

  • PhenobarbitalbarbiturateModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • PhenytoinanticonvulsantModerate

    Antiepileptic Drugs Clinical Impact Concomitant administration of phenytoin or carbamazepine with topiramate in patients with epilepsy, decreased plasma concentrations of topiramate by 48% and 40%, respectively, when compared to topiramate given alone [see Clinical Pharmacology (12.3) ] . (Phentermine and topiramate label, Drug interactions)

  • PioglitazonethiazolidinedioneModerate

    Pioglitazone Clinical Impact A decrease in the exposure of pioglitazone and its active metabolites were noted with the concurrent use of pioglitazone and topiramate in a clinical trial. (Phentermine and topiramate label, Drug interactions)

  • PitolisantQT-prolonging drugModerate

    Strong CYP3A4 Inducers: Decreased exposure of WAKIX; consider dosage adjustment of WAKIX ( 2.6 , 7.1 ) (Pitolisant label, Drug interactions)

  • Posaconazoleazole antifungalModerate

    Concomitant Use with Midazolam : Noxafil can prolong hypnotic/sedative effects. (Posaconazole label, Warnings and precautions)

  • PrednisolonecorticosteroidModerate

    CYP 3A4 inducers (e.g. barbiturates, phenytoin, carbamazepine, and rifampin): Drugs such as barbiturates, phenytoin, ephedrine, and rifampin, which induce hepatic microsomal drug metabolizing enzyme activity may enhance metabolism of prednisolone and require that the dosage of Orapred be increased. (Prednisolone label, Drug interactions)

  • PrednisonecorticosteroidModerate

    CYP 3A4 inducers and inhibitors: May, respectively, increase or decrease clearance of corticosteroids, necessitating dose adjustment. (Prednisone label, Drug interactions)

  • PregabalinanticonvulsantModerate

    When the decision is made to co-prescribe LYRICA CR with another CNS depressant, particularly an opioid, or to prescribe LYRICA CR to patients with underlying respiratory impairment, monitor patients for symptoms of respiratory depression and sedation, and consider initiating LYRICA CR at a low dose. (Pregabalin label, Warnings and precautions)

  • PrimidoneanticonvulsantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • ProchlorperazineantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • ProgesteroneprogestinModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • PromethazineantihistamineModerate

    The impairment may be amplified by concomitant use of other central-nervous-system depressants such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore such agents should either be eliminated or given in reduced dosage in the presence of promethazine… (Promethazine label, Warnings)

  • PropofolCNS depressantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Propranololbeta blockerModerate

    Impact of Other Drugs on Propranolol CYP2D6, CYP1A2 and CYP2C19 Inhibitors: CYP2D6 inhibitors (e.g. bupropion, fluoxetine, paroxetine, quinidine), CYP1A2 inhibitors (e.g., ciprofloxacin, enoxamine, fluvoxamine) and CYP2C19 inhibitors (e.g., fluconazole, fluvoxamine, ticlopidine) increase exposure to propranolol when co-administered with INNOPRAN XL. (Propranolol label, Drug interactions)

  • QuetiapineantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • Ramelteonsedative-hypnoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • RepaglinidemeglitinideModerate

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

  • RifampinantibioticModerate

    …Hormonal Contraceptives Prevention or Management: Advise patients to change to non-hormonal methods of birth control during rifampin therapy Estrogens Decrease exposure Progestins Anticonvulsants Phenytoin Administered with rifampin 450 mg daily Decrease exposure Antiarrhythmics Disopyramide Decrease exposure Mexiletine Decrease exposure Quinidine Decrease exposure… (Rifampin label, Drug interactions)

  • RisperidoneantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • RufinamideanticonvulsantModerate

    Table 6: Summary of drug-drug interactions of BANZEL with other antiepileptic drugs AED Co-administered Influence of Rufinamide on AED concentration a) Influence of AED on Rufinamide concentration Carbamazepine Decrease by 7 to 13% b) Decrease by 19 to 26% Dependent on dose of carbamazepine Lamotrigine Decrease by 7 to 13% b) No Effect Phenobarbital Increase… (Rufinamide label, Drug interactions)

  • ScopolamineanticholinergicModerate

    Weigh this potential risk against the benefits before prescribing TRANSDERM SCŌP to patients with a history of seizures, including those receiving anti-epileptic medication or who have risk factors that can lower the seizure threshold. (Scopolamine label, Warnings and precautions)

  • SertralineSSRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St. (Sertraline label, Warnings and precautions)

  • Sotalolbeta blockerModerate

    Beta-2-Receptor Stimulants Beta-agonists such as albuterol, terbutaline and isoproterenol may have to be administered in increased dosages when used concomitantly with sotalol. (Sotalol label, Drug interactions)

  • Spironolactonealdosterone antagonistModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • Spironolactone and hydrochlorothiazidealdosterone antagonistModerate

    Concomitant administration of hydrochlorothiazide alone with topiramate alone has been shown to increase the C max and AUC of topiramate by 27% and 29%, respectively. (Phentermine and topiramate label, Drug interactions)

  • Suvorexantsedative-hypnoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • TacrolimusimmunosuppressantModerate

    Risk of Rejection with Strong CYP3A Inducers and Risk of Serious Adverse Reactions with Strong CYP3A Inhibitors The concomitant use of strong CYP3A inducers may increase the metabolism of tacrolimus, leading to lower whole blood trough concentrations and greater risk of rejection. (Tacrolimus label, Warnings and precautions)

  • TadalafilPDE5 inhibitorModerate

    CYP3A4 inhibitors (e.g. ketoconazole, ritonavir) increase CIALIS exposure ( 2.7 , 5.10 , 7.2 ) requiring dose adjustment: CIALIS for use as needed: no more than 10 mg every 72 hours CIALIS for once daily use: dose not to exceed 2.5 mg CYP3A4 inducers (e.g. rifampin) decrease CIALIS exposure ( 7.2 ). (Tadalafil label, Drug interactions)

  • TemazepambenzodiazepineModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • TerbinafineantifungalModerate

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

  • TetrabenazineVMAT2 inhibitorModerate

    Alcohol or Other Sedating Drugs Concomitant use of alcohol or other sedating drugs may have additive effects and worsen sedation and somnolence [see Warnings and Precautions (5.7) ] . (Tetrabenazine label, Drug interactions)

  • TheophyllinemethylxanthineModerate

    25% increase Diazepam Benzodiazepines increase CNS concentrations of adenosine, a potent CNS depressant, while theophylline blocks adenosine receptors. (Theophylline label, Drug interactions)

  • TiagabineanticonvulsantModerate

    Use of tiagabine HCl without enzyme-inducing antiepileptic drugs results in blood levels about twice those attained in the studies on which current dosing recommendations are based (see DOSAGE AND ADMINISTRATION ). (Tiagabine label, Warnings)

  • TinidazoleantibioticModerate

    Phenytoin, fosphenytoin: Adjustment of anticonvulsant and/or tinidazole dose(s) may be needed ( 7.1, 7.2 ) (Tinidazole label, Drug interactions)

  • TiotropiumanticholinergicModerate

    Concomitant Respiratory Medications SPIRIVA RESPIMAT has been used concomitantly with short-acting and long-acting sympathomimetic (beta-agonists) bronchodilators, methylxanthines, oral and inhaled steroids, antihistamines, mucolytics, leukotriene modifiers, cromones, and anti-IgE treatment without increases in adverse reactions. (Tiotropium label, Drug interactions)

  • Tizanidinemuscle relaxantModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

  • TofacitinibimmunosuppressantModerate

    …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)

  • TopiramateanticonvulsantModerate

    Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl… (Phentermine and topiramate label, Drug interactions)

  • Torsemideloop diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • TrazodoneantidepressantModerate

    CYP3A4 Inducers: Increase in RALDESY dosage may be necessary ( 2.5 , 7 ). (Trazodone label, Drug interactions)

  • Treprostinilprostaglandin analogModerate

    Co-administration of a CYP2C8 enzyme inducer (e.g., rifampin) may decrease exposure to treprostinil. (Treprostinil label, Warnings and precautions)

  • TriamcinolonecorticosteroidModerate

    Hepatic enzyme inducers (e.g., barbiturates, phenytoin, carbamazepine, rifampin): Drugs which induce hepatic microsomal drug metabolizing enzyme activity may enhance the metabolism of corticosteroids and require that the dosage of the corticosteroid be increased. (Triamcinolone label, Drug interactions)

  • Triamterenepotassium-sparing diureticModerate

    In addition, when phentermine and topiramate extended-release capsules are used in conjunction with nonpotassium sparing diuretics this may further potentiate potassium-wasting. (Phentermine and topiramate label, Warnings and precautions)

  • Triamterene and hydrochlorothiazidepotassium-sparing diureticModerate

    Concomitant administration of hydrochlorothiazide alone with topiramate alone has been shown to increase the C max and AUC of topiramate by 27% and 29%, respectively. (Phentermine and topiramate label, Drug interactions)

  • TrihexyphenidylanticholinergicModerate

    Concurrent use of alcohol or other CNS depressants with trihexyphenidyl HCl may cause increased sedative effects. (Trihexyphenidyl label, Drug interactions)

  • Valsartan and hydrochlorothiazideangiotensin II receptor blocker (ARB)Moderate

    Concomitant administration of hydrochlorothiazide alone with topiramate alone has been shown to increase the C max and AUC of topiramate by 27% and 29%, respectively. (Phentermine and topiramate label, Drug interactions)

  • VenlafaxineSNRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, meperidine, methadone, busipirone, amphetamines, and St. (Venlafaxine label, Warnings and precautions)

  • Verapamilcalcium channel blockerModerate

    CYP3A4 inducers decrease verapamil levels ( 7.1 ) (Verapamil label, Drug interactions)

  • VilazodoneSSRIModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, meperidine, methadone, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. (Vilazodone label, Warnings and precautions)

  • Voriconazoleazole antifungalModerate

    Eszopiclone (CYP3A4 Inhibition) Not Studied In Vivo or In Vitro , but Drug Plasma Exposure Likely to be Increased which may Increase the Sedative Effect of Eszopiclone Dose reduction of eszopiclone is recommended. (Voriconazole label, Drug interactions)

  • VortioxetineantidepressantModerate

    The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, meperidine, methadone, buspirone, amphetamines, and St. (Vortioxetine label, Warnings and precautions)

  • ZiprasidoneantipsychoticModerate

    The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence. (Phentermine and topiramate label, Warnings and precautions)

Minor mentions (14)

  • AcarboseantidiabeticMinor

    These drugs include the thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel-blocking drugs, and isoniazid. (Acarbose label, Drug interactions)

  • AspirinNSAIDMinor

    (tartrazine) sensitivity in the general population is low, it is frequently seen in patients who also have aspirin hypersensitivity. (Phentermine and topiramate label, Warnings and precautions)

  • CephalexincephalosporinMinor

    Anticonvulsant therapy can be given if clinically indicated. (Cephalexin label, Warnings and precautions)

  • Epoetin alfaMinor

    The “gasping syndrome” is characterized by central nervous system (CNS) depression, metabolic acidosis, and gasping respirations. (Epoetin alfa label, Warnings and precautions)

  • GlyburidesulfonylureaMinor

    These drugs include the thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blocking drugs, and isoniazid. (Glyburide label, Drug interactions)

  • HydroxychloroquineQT-prolonging drugMinor

    Antiepileptics The activity of antiepileptic drugs might be impaired if co-administered with PLAQUENIL. (Hydroxychloroquine label, Drug interactions)

  • Insulin regular (human)insulinMinor

    Atypical Antipsychotics (e.g., olanzapine and clozapine), Corticosteroids, Danazol, Diuretics, Estrogens, Glucagon, Isoniazid, Niacin, Oral Contraceptives, Phenothiazines, Progestogens (e.g., in oral contraceptives), Protease inhibitors, Somatropin, Sympathomimetic Agents (e.g., albuterol, epinephrine, terbutaline) and Thyroid Hormones. (Insulin regular (human) label, Drug interactions)

  • IpratropiumanticholinergicMinor

    ATROVENT HFA has been used concomitantly with other drugs, including sympathomimetic bronchodilators, methylxanthines, oral and inhaled steroids commonly used in the treatment of COPD. (Ipratropium label, Drug interactions)

  • KetorolacNSAIDMinor

    Antiepileptic Drugs Sporadic cases of seizures have been reported during concomitant use of ketorolac tromethamine and antiepileptic drugs (phenytoin, carbamazepine). (Ketorolac label, Drug interactions)

  • Labetalolbeta blockerMinor

    Labetalol has also been reported to produce a false-positive test for amphetamine when screening urine for the presence of drugs using the commercially available assay methods. (Labetalol label, Drug interactions)

  • LevetiracetamanticonvulsantMinor

    Other Antiepileptic Drugs Potential drug interactions between levetiracetam and other AEDs (carbamazepine, gabapentin, lamotrigine, phenobarbital, phenytoin, primidone and valproate) were also assessed by evaluating the serum concentrations of levetiracetam and these AEDs during placebo-controlled clinical studies. (Levetiracetam label, Drug interactions)

  • Prazosinalpha blockerMinor

    …to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout–allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol (see WARNINGS however),… (Prazosin label, Drug interactions)

  • RifaximinantibioticMinor

    CYP3A4 Substrates An in vitro study has suggested that rifaximin induces CYP3A4 [see Clinical Pharmacology ( 12.3 )] . (Rifaximin label, Drug interactions)

  • RiociguatvasodilatorMinor

    Strong CYP3A inducers: Strong inducers of CYP3A (for example, rifampin, phenytoin, carbamazepine, phenobarbital or St. (Riociguat label, Drug interactions)

No significant interaction reported (1)

  • Montelukastleukotriene receptor antagonistNo interaction

    …adjustment is needed when SINGULAIR is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, fexofenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3) ]. (Montelukast label, Drug interactions)

Check Phentermine and topiramate against everything you take. Add your full list; every pair is checked at once.

Open in the checker

Not medical advice. Severity reflects the label's wording, not your circumstances. A "major" flag can be routine under supervision and a "minor" one can matter at high doses. Ask a pharmacist.