Clonazepam in the treatment of epilepsy. A clinical long-term follow-up study.

Sixty-eight patients with various types of epileptic seizures have been treated with clonazepam (Rivotril). Fifty-four patients could be evaluated. In 44 patients, clonazepam was used as a supplement to insufficient previous medication. Ten patients received clonazepam alone. The mean duration of treatment was 2 years and 7 months. Thirty-three patients are still on clonazepam, with a mean duration of treatment of 3 years and 4 months. In 34 patients (63%) a reduction of more than 50% was seen in the seizure frequency of the only type suffered by a patient, or of one of several types. No significant decrease in antiepileptic potency with time was observed. Medication was withdrawn in a total of 21 of the 54 patients because of freedom from seizures (2 patients), lack of effect (7 patients), increased frequency of seizures (3 patients), or lack of cooperation and/or side-effects (3 patients). In 5 patients, the drug may have provoked new types of epileptic seizure. This long-term follow-up study seems to substantiate the favorable antiepileptic properties of clonazepam.