Effects of preoperatively administered carbamazepine and phenytoin on rocuronium-induced neuromuscular block under sevoflurane anesthesia: a retrospective clinical study.

We examined the effects of preoperatively administered phenytoin and carbamazepine on rocuronium-induced neuromuscular block under sevoflurane anesthesia in this retrospective clinical study. When compared to patients without anticonvulsant therapy (n = 16), the recovery index (i.e., the time required from 25% of spontaneous return of T1 to 75% of spontaneous return of T1) was significantly lower in patients with anticonvulsant therapy using carbamazepine and/ or phenytoin (n = 17); however, no significant dose-dependent effects of carbamazepine as well as phenytoin on the recovery index were detected. Further studies are required to elucidate the mechanisms underlying the modifying effects of carbamazepine and phenytoin on pharmacokinetics and pharmacodynamics of rocuronium.