Potential pharmacokinetic interactions of or with Levetiracetam were assessed in clinical pharmacokinetic studies (phenytoin, valproate, warfarin. digoxin, oral contraceptive. probenecid) and through pharmacokinetic screening in the placebo-controlled clinical studies in epilepsy patients. Symptoms of carbamazepine toxicity have been reported when Levetiracetam was added to carbamazepine therapy; this interaction appeared to be due to Pharmacodynamics mechanism as blood levels of carbamazepine and its metabolite were not altered.