SUMMARY OF DRUG-DRUG INTERACTIONS*1

A summary of drug-drug interactions when taking BANZEL (rufinamide). Carbamazepine is decreased 7-13% when co-administered with BANZEL, and it decreases BANZEL concentration by 19-26% (depending on the dose of carbamazepine); lamotrigine is decreased by 7-13% when co-administered with BANZEL and has no effect on the BANZEL concentration; phenobarbital is increased by 8-13% when co-administered with BANZEL, and the concentration of BANZEL is decreased by 25-46% (independent of dose or concentration of phenobarbital); phenytoin is increased by 7-21% when co-administered with BANZEL while BANZEL concentration is decreased by 25-46% (independent of dose or concentration of phenytoin); topiramate has no effect on BANZEL concentration and is not affected by BANZEL concentration; BANZEL has no effect on valproate concentration when co-administered with BANZEL but can increase BANZEL concentration by <16% to 70% (dependent on the concentration of valproate); the influence of BANZEL concentration on primidone concentration has not been investigated;however primidone decreases the concentration of BANZEL by 25-46% (independent of dose or concentration of primidone). The influence of BANZEL on benzodiazepine concentration has not been investigated; however there is no effect on BANZEL concentration when coadministered.
AED coadministered
Influence of BANZEL® on AED concentration
Influence of AED on BANZEL® concentration
Carbamazepine
Decrease by 7%-13%
Decrease by 19%-26% (Dependent on dose of carbamazepine)
Lamotrigine
Decrease by 7%-13%
No effect
Phenobarbital
Increase by 8%-13%
Decrease by 25%-46%§|| (Independent of dose or concentration of phenobarbital)
Phenytoin
Increase by 7%-21%
Decrease by 25%-46%§|| (Independent of dose or concentration of phenytoin)
Topiramate
No effect
No effect
Valproate
No effect
Increase by <16%-70%§ (Dependent on concentration of valproate)
Primidone
Not investigated
Decrease by 25%-46%§|| (Independent of dose or concentration of primidone)
Benzodiazepines
Not investigated
No effect


*Based on a population pharmacokinetic analysis.
Predictions are based on BANZEL concentrations at the maximum recommended dose of BANZEL.
Maximum changes predicted to be in children and in patients who achieve significantly higher levels of BANZEL, as the effect of BANZEL on these AEDs is concentration dependent.
§Larger effects in children at high doses/concentrations of AEDs.
||Phenobarbital, primidone, and phenytoin were treated as a single covariate (phenobarbital-type inducers) to examine the effect of these agents on BANZEL clearance.
All compounds of the benzodiazepine class were pooled to examine for class effect on BANZEL clearance.

Effects of BANZEL® on valproate

BANZEL clearance was decreased by valproate. In children, valproate administration may lead to elevated levels of BANZEL by up to 70%1

  • When adding valproate to BANZEL, begin valproate at a low dose and titrate to a clinically effective dose
  • When adding BANZEL to valproate, begin BANZEL at a dose lower than 10 mg/kg/day for children or 400 mg/day for adults

Effects of BANZEL® on other medications

  • BANZEL may render hormonal contraceptives less effective. Additional non-hormonal forms of contraception are recommended when using BANZEL1
  • Use caution when administering with other drugs that shorten the QT interval1

BANZEL® enzyme inhibition

Based on in vitro studies, BANZEL shows little or no inhibition of most cytochrome P450 enzymes at clinically relevant concentrations, with weak inhibition of CYP2E1. Drugs that are substrates of CYP2E1 (eg, chlorzoxazone) may have increased plasma levels in the presence of BANZEL, but this has not been studied.1

Use of BANZEL® in specific populations

  • Pregnancy Category C
    • BANZEL should be used during pregnancy only if the potential benefit justifies the risk to the fetus
  • Nursing Mothers
    • Because of the potential for serious adverse reactions in nursing infants from BANZEL, a decision should be made whether to discontinue nursing or discontinue the drug
  • No dose adjustments are required for patients with renal impairment1
    • Hemodialysis may reduce exposure to a limited extent; adjusting the BANZEL dose should be considered
  • Use in patients with severe hepatic impairment is not recommended1
  • Use caution in patients with mild to moderate hepatic impairment1
  • Reference: 1. BANZEL® (rufinamide) prescribing information, Eisai Inc.