Oxcarbazepine and Phenobarbital interaction

Oxcarbazepine and Phenobarbital: the Oxcarbazepine prescribing label describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Oxcarbazepine (Trileptal) label · effective 2025-12-16

Moderate

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

Drug interactionsnames PhenobarbitalView label on DailyMed
Moderate

Effect of Other Drugs on TRILEPTAL Strong inducers of cytochrome P450 enzymes and/or inducers of UGT (e.g., rifampin, carbamazepine, phenytoin and phenobarbital) have been shown to decrease the plasma/serum levels of MHD, the active metabolite of TRILEPTAL (25% to 49%) [see Clinical Pharmacology (12.3)] .

Drug interactionsnames PhenobarbitalView label on DailyMed
Moderate

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

Warnings and precautionsby drug classView label on DailyMed
Minor

…controlled epilepsy studies, 2.5% of TRILEPTAL-treated patients (38/1524) had a sodium of less than 125 mmol/L at some point during treatment, compared to no such patients assigned placebo or active control (carbamazepine and phenobarbital for adjunctive and monotherapy substitution studies, and phenytoin and valproate for the monotherapy initiation studies).

Warnings and precautionsnames PhenobarbitalView label on DailyMed

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.