What is the interaction between Brivacetam (Brivaracetam) and carbimazole?

Brivacetam and Carbimazole Drug Interaction

There is no clinically significant drug interaction between brivacetam and carbimazole, and these medications can be safely co-administered without dose adjustment.

Mechanism Analysis

Brivacetam has a favorable pharmacokinetic profile with minimal interaction potential:

• Brivacetam does not interact with most metabolizing enzymes and drug transporters, allowing administration without dose adjustment for most concomitant medications 1
• Brivacetam is extensively biotransformed but exhibits linear and dose-proportional pharmacokinetics at therapeutic doses 1
• The drug does not interfere with medications using common metabolic routes 1

Carbimazole Metabolic Pathway

Carbimazole (an antithyroid medication) is not metabolized through the cytochrome P450 pathways that would interact with brivacetam:

• Carbimazole is a prodrug that is rapidly converted to methimazole in the body
• It does not function as a CYP3A4 inducer or inhibitor, which are the primary pathways that could affect brivacetam levels
• Carbimazole is distinct from carbamazepine (the antiepileptic drug that DOES interact with brivacetam) 2

Important Distinction: Carbimazole vs. Carbamazepine

Critical caveat: Do not confuse carbimazole with carbamazepine:

• Carbamazepine (the antiepileptic) is a strong CYP3A4 inducer that moderately lowers brivacetam plasma concentrations by approximately 32% 1, 3, 4
• Carbimazole (the antithyroid medication) has no such interaction and operates through completely different metabolic pathways
• When carbamazepine is co-administered with brivacetam, no dose adjustment is typically needed despite the reduced exposure 1, 5

Clinical Recommendations

No special monitoring or dose adjustments are required when combining brivacetam with carbimazole:

• Administer both medications at their standard therapeutic doses 1
• No separation of administration times is necessary 2
• Monitor for the individual side effects of each medication separately rather than anticipating combined adverse effects 6

Drugs That DO Interact with Brivacetam

For context, only strong enzyme inducers significantly affect brivacetam levels:

• Rifampin requires dose adjustment consideration when co-administered with brivacetam 1
• St. John's wort should be used with caution when adding or ending treatment 1
• Carbamazepine, phenytoin, and phenobarbital moderately lower brivacetam concentrations but typically do not require dose adjustment 1, 5