Increased seizures after discontinuing carbamazepine: Results from the gabapentin monotherapy trial

Studies in patients with epilepsy undergoing telemetry evaluation for surge ry have suggested that discontinuation of carbamazepine (CBZ) is associated with increased seizures. The period of observation in that setting, howeve r, was limited to a few days. The authors reviewed the occurrence of seizur es in patients with epilepsy who had all their antiepileptic medications di scontinued during an 8-week period, converted to gabapentin monotherapy, an d observed for 26 weeks as part of the gabapentin trial #945-082. Two hundr ed and seventy-five patients were enrolled. Kaplan-Meier estimates of time to exit for all patients showed that 18% of patients previously treated wit h CBZ completed the study as compared with 30% of the patients receiving ot her antiepileptic medications. Increase in the frequency of seizures was ma ximal in the 2 weeks following CBZ discontinuation. Seizures increased both in frequency and severity but no new seizure types were observed. The find ings in this study show that removal of CBZ is associated with increased fr equency of seizures in patients with a previous history of epilepsy with in completely controlled seizures. The period of maximal increase was the firs t 2 weeks after CBZ discontinuation.