Phenobarbital interactions

Abuse and misuse of phenobarbital commonly involve concomitant use of other drugs, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes [see Warnings and Precaution (5.3)]. (Phenobarbital label, Boxed warning)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

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

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)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Concomitant administration with oxcarbazepine or phenobarbital is not recommended. (Bictegravir, emtricitabine, and tenofovir alafenamide label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

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)

SEZABY is contraindicated in patients with: acute porphyrias [see Warnings and Precautions (5.8)], or a history of hypersensitivity reaction to phenobarbital or other barbiturates [see Warnings and Precautions (5.7)] Acute porphyrias (4) (Phenobarbital label, Contraindications)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS Depressants The concomitant use of EQUETRO and other CNS depressants can increase the risk of respiratory depression, profound sedation, hypotension, and syncope. (Carbamazepine label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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)

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)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

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)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

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

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

• Respiratory Depression: May occur with NEURONTIN when used with concomitant central nervous system (CNS) depressants, including opioids, or in the setting of underlying respiratory impairment. (Gabapentin label, Warnings and precautions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

To avoid phenytoin intoxication, appropriate adjustment of the anticonvulsant should be made 5,6 . (Isoniazid label, Drug interactions)

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

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

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

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)

CYP2B6 Inducers (e.g., ritonavir, lopinavir, efavirenz, carbamazepine, phenobarbital, and phenytoin) may reduce efficacy by reducing bupropion exposure, avoid concomitant use. (Naltrexone and bupropion label, Drug interactions)

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

…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)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

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

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

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

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

Phenelzine sulfate should not be used in combination with dextromethorphan or with CNS depressants such as alcohol and certain narcotics. (Phenelzine label, Contraindications)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

• Respiratory Depression : May occur with LYRICA when used with concomitant CNS depressants or in the setting of underlying respiratory impairment. (Pregabalin label, Warnings and precautions)

SEZABY is contraindicated in patients with: acute porphyrias [see Warnings and Precautions (5.8)], or a history of hypersensitivity reaction to phenobarbital or other barbiturates [see Warnings and Precautions (5.7)] Acute porphyrias (4) (Phenobarbital label, Contraindications)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

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

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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)

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)

Therefore the use of strong cytochrome P450 inducers (e.g., rifampicin, phenobarbital, carbamazepine, and phenytoin) with DALIRESP is not recommended [see Warnings and Precautions (5.4) and Clinical Pharmacology (12.3) ]. (Roflumilast label, Drug interactions)

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)

• Central Nervous System Depression Xyrem (sodium oxybate) is a CNS depressant. (Sodium oxybate label, Boxed warning)

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

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

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

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation,… (Phenobarbital label, Boxed warning)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

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

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

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

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

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

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)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

CNS depressants: Closely monitor for sedation and respiratory depression. (Phenobarbital label, Drug interactions)

By decreasing the gastrointestinal absorption of primidone, acetazolamide may decrease serum concentrations of primidone and its metabolites, with a consequent possible decrease in anticonvulsant effect. (Acetazolamide label, Drug interactions)

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)

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)

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

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

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)

Alcohol, barbiturates, or narcotics - potentiation of orthostatic hypotension may occur. (Bisoprolol and hydrochlorothiazide label, Precautions)

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

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)

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. (Budesonide and formoterol label, Warnings and precautions)

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)

Phenytoin/Phenobarbital The coadministration of phenytoin or phenobarbital will not affect plasma concentrations of calcitriol, but may reduce endogenous plasma levels of 25(OH)D 3 by accelerating metabolism. (Calcitriol label, Drug interactions)

Examples: Rifampin, phenytoin, phenobarbital, ritonavir Insulin or Insulin Secretagogues Clinical Impact: The risk of hypoglycemia is increased when INVOKANA is used concomitantly with insulin secretagogues (e.g., sulfonylurea) or insulin. (Canagliflozin label, Drug interactions)

Phenobarbital and Clobazam: Reduce dosage as needed when used concomitantly with XCOPRI. (Cenobamate label, Drug interactions)

Drug Interactions Cholestyramine for Oral Suspension USP may delay or reduce the absorption of concomitant oral medication such as phenylbutazone, warfarin, thiazide diuretics (acidic), or propranolol (basic), as well as tetracycline, penicillin G, phenobarbital, thyroid and thyroxine preparations, estrogens and progestins, and digitalis. (Cholestyramine label, Drug interactions)

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

John’s Wort rifampin oxcarbazepine octreotide phenobarbital orlistat phenytoin sulfinpyrazone terbinafine ticlopidine Bosentan Coadministration of bosentan (250 to 1000 mg every 12 hours based on tolerability) and cyclosporine (300 mg every 12 hours for 2 days then dosing to achieve a C min of 200 to 250 ng/mL) for 7 days in healthy subjects resulted in decreases… (Cyclosporine label, Drug interactions)

The concomitant use of Exjade with potent UGT inducers (e.g., rifampicin, phenytoin, phenobarbital, ritonavir) may result in a decrease in Exjade efficacy due to a possible decrease in deferasirox concentration. (Deferasirox label, Drug interactions)

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)

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)

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

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

Potential additive effects when used in combination with CNS depressants or sedating antihistamines. (Doxepin label, Warnings and precautions)

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

Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampin, topiramate and products containing St. (Drospirenone and ethinyl estradiol label, Drug interactions)

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

Phenobarbital or Primidone: Higher dosage of APTIOM may be necessary. (Eslicarbazepine label, Drug interactions)

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)

John's Wort preparations (Hypericum perforatum), phenobarbital, carbamazepine, and rifampin may reduce plasma concentrations of estrogens, possibly resulting in a decrease in therapeutic effects and/or changes in the uterine bleeding profile. (Estradiol label, Drug interactions)

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)

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)

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

Barbiturates, phenytoin, or rifampin —increased metabolic clearance of fludrocortisone acetate because of the induction of hepatic enzymes. (Fludrocortisone label, Drug interactions)

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)

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, oral corticosteroids) should be monitored and treated with established standards of care. (Fluticasone and salmeterol label, Warnings and precautions)

These antiepileptic drugs lower folate levels, and folic acid supplements can in turn lower blood levels of the drug. (NIH Office of Dietary Supplements, Folate)

…including glimepiride, leading to worsening glycemic control: danazol, glucagon, 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… (Glimepiride label, Drug interactions)

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)

Barbiturates usually depress griseofulvin activity by decreasing plasma levels and concomitant administration may require a dosage adjustment of the antifungal agent. (Griseofulvin label, Drug interactions)

Consider the potential for additive sedative effects with CNS depressant drugs. (Guanfacine label, Warnings and precautions)

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)

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

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)

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

Carbamazepine, phenytoin, phenobarbital, primidone, and rifampin decrease lamotrigine concentrations by approximately 40%. (Lamotrigine label, Drug interactions)

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)

Enzyme inducers (e.g., CYP3A4) : May decrease the effectiveness of TYBLUME or increase breakthrough bleeding. (Levonorgestrel and ethinyl estradiol label, Drug interactions)

Drug or Drug Class Effect Phenobarbital Rifampin Phenobarbital has been shown to reduce the response to thyroxine. (Levothyroxine label, Drug interactions)

…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)

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

Drug or Drug Class Effect Phenobarbital Rifampin Phenobarbital has been shown to reduce the response to thyroxine. (Liothyronine label, Drug interactions)

Alcohol, barbiturates, or narcotics - potentiation of orthostatic hypotension may occur. (Lisinopril and hydrochlorothiazide label, Drug interactions)

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)

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

MPA Injectable Suspension, USP can pose an additional risk in patients with risk factors for osteoporosis (e.g., metabolic bone disease, chronic alcohol and/or tobacco use, anorexia nervosa, strong family history of osteoporosis or chronic use of drugs that can reduce bone mass such as anticonvulsants or corticosteroids). (Medroxyprogesterone label, Warnings and precautions)

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)

Concomitant use of central nervous system (CNS) depressants or drugs associated with EPS may increase this effect (e.g., alcohol, sedatives, hypnotics, opiates, and anxiolytics). (Metoclopramide label, Warnings and precautions)

Alcohol, Barbiturates, And Narcotics The hypotensive effects of these drugs may be potentiated by the volume contraction that may be associated with metolazone therapy. (Metolazone label, Drug interactions)

Inducers of CYP450 Liver Enzymes The simultaneous administration of LIKMEZ and drugs that induce microsomal liver enzymes, such as phenytoin or phenobarbital, may accelerate the elimination of metronidazole, resulting in reduced plasma concentrations of metronidazole. (Metronidazole label, Drug interactions)

John's Wort, tramadol, tryptophan, buspirone Strong CYP3A Inducers Clinical Impact The concomitant use of strong CYP3A inducers with REMERON/REMERONSolTab decreases the plasma concentration of mirtazapine [see Clinical Pharmacology (12.3) ] . (Mirtazapine label, Drug interactions)

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)

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)

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

Contraceptive effectiveness may be reduced when hormonal contraceptives are co-administered with antibiotics, anticonvulsants, and other drugs that increase the metabolism of contraceptive steroids. (Norethindrone label, Drug interactions)

Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampicin, topiramate, rifabutin, rufinamide, aprepitant, and products containing St. (Norgestimate and ethinyl estradiol label, Drug interactions)

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)

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)

Carbamazepine, Phenytoin, and Phenobarbital: Decreased plasma levels of MHD (the active metabolite). (Oxcarbazepine label, Drug interactions)

Table 3 Effects of Other Drugs on Paroxetine Concomitant Drug Name Effect of Concomitant Drug on Paroxetine Clinical Recommendations Phenobarbital Decreased paroxetine exposure Phenytoin Decreased paroxetine exposure Fosamprenavir/Ritonavir Decreased plasma concentration of paroxetine Monitor clinical effect of BRISDELLE. (Paroxetine label, Drug interactions)

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)

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)

Additionally, consider alternatives to structurally similar drugs such as carboxamides (e.g., carbamazepine) and hydantoins (e.g., phenytoin) in these same patients. (Phenobarbital label, Warnings and precautions)

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)

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

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)

…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)

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)

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)

Drugs that induce CYP3A4 (e.g., phenytoin, carbamazepine, nafcillin, phenobarbital, and rifampin) should be used with caution. (Selegiline label, Drug interactions)

Alcohol, barbiturates, or narcotics: Potentiation of orthostatic hypotension may occur. (Spironolactone and hydrochlorothiazide label, Drug interactions)

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)

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

30% increase Phenobarbital (PB) Similar to aminoglutethimide. (Theophylline label, Drug interactions)

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)

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

…exposure to tofacitinib Intervention Dosage modification of XELJANZ/XELJANZ XR is recommended [see Dosage and Administration (2) , Clinical Pharmacology, Figure 3 (12.3) ] Strong CYP3A4 Inducers (e.g., rifampin) Clinical Impact Decreased exposure to tofacitinib and may result in loss of or reduced clinical response Intervention Concomitant use with XELJANZ/XELJANZ… (Tofacitinib label, Drug interactions)

Because of the potential of topiramate to cause CNS depression, as well as other cognitive and/or neuropsychiatric adverse reactions, TROKENDI XR should be used with extreme caution if used in combination with alcohol and other CNS depressants [see Contraindications (4) and Warnings and Precautions (5.7) ]. (Topiramate label, Drug interactions)

Excessive reduction of blood glucose (additive effect) f CNS depressant agents (including opioids, alcohol, sedatives, hypnotics) Use with caution d Increased CNS depression Dietary supplements containing sympathomimetics Contraindicated a Antidepressants including but not limited to: Other MAOIs (e.g., linezolid, intravenous methylene blue, selective MAOIs)… (Tranylcypromine label, Drug interactions)

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

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)

Drug Interactions Cannabinoids, barbiturates, opiates, and alcohol may have additive effects with trihexyphenidyl HCl, and thus, an abuse potential exists. (Trihexyphenidyl label, Drug interactions)

Phenobarbital Phenobarbital therapy may increase verapamil clearance. (Verapamil label, Drug interactions)

CYP3A4 Inducers: Consider increasing VIIBRYD dosage by 2-fold, up to 80 mg once-daily over 1 to 2 weeks when used concomitantly with strong CYP3A4 inducers for greater than 14 days ( 2.4 , 7 ). (Vilazodone label, Drug interactions)

…etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral… (Warfarin label, Drug interactions)

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

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

Use alternative treatment that does not include carbamazepine where possible for INSTI-experienced patients with certain INSTI-associated resistance substitutions or clinically suspected INSTI resistance. b Oxcarbazepine Phenytoin Phenobarbital St. (Dolutegravir label, Drug interactions)

Drugs Metabolized by CYP3A Results of in vitro studies demonstrate that duloxetine does not inhibit or induce CYP3A activity. (Duloxetine label, Drug interactions)

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

Data are more extensive with respect to phenytoin and phenobarbital, but these are also the most commonly prescribed anticonvulsants; less systematic or anecdotal reports suggest a possible similar association with the use of all known anticonvulsant drugs. (Ethosuximide label, Warnings)

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

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)

…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), and quinidine; and (6) analgesics, antipyretics… (Prazosin label, Drug interactions)

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

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

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

…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)