Phenobarbital, hyoscyamine, atropine, and scopolamine and Rufinamide interaction

Phenobarbital, hyoscyamine, atropine, and scopolamine and Rufinamide: the Rufinamide prescribing label describes 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 Rufinamide (Banzel) label · effective 2022-12-15

Moderate

…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 by 8 to 13% b) Decrease by 25 to 46% c) ’ d) Independent of dose or concentration of phenobarbital Phenytoin Increase by 7 to 21% b) Decrease by 25 to 46% c)…

Drug interactionsnames Phenobarbital, hyoscyamine, atropine, and scopolamineView label on DailyMed
Moderate

Effects of Other AEDs on BANZEL Potent cytochrome P450 enzyme inducers, such as carbamazepine, phenytoin, primidone, and phenobarbital, appear to increase the clearance of BANZEL (see Table 6).

Drug interactionsnames Phenobarbital, hyoscyamine, atropine, and scopolamineView label on DailyMed
Minor

Effects of BANZEL on other AEDs Population pharmacokinetic analysis of average concentration at steady state of carbamazepine, lamotrigine, phenobarbital, phenytoin, topiramate, and valproate showed that typical rufinamide C avss levels had little effect on the pharmacokinetics of other AEDs.

Drug interactionsnames Phenobarbital, hyoscyamine, atropine, and scopolamineView label on DailyMed
No interaction

Given that the majority of clearance of BANZEL is via a non-CYP-dependent route, the observed decreases in blood levels seen with carbamazepine, phenytoin, phenobarbital, and primidone are unlikely to be entirely attributable to induction of a P450 enzyme.

Drug interactionsnames Phenobarbital, hyoscyamine, atropine, and scopolamineView 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.