Reduction of seizures with low-dose clonazepam in children with epilepsy

The acute effects of low-dose clonazepam on seizure frequency in children with epilepsy was evaluated. In an open study, 19 children with epilepsy (15 generalized and four partial) were examined during hospitalization with recordings of seizures by trained personnel. Seizures were counted during two 24-hour periods: before and after a single intramuscular injection of clonazepam 0.01-0.04 mg/kg body weight. Plasma concentrations of clonazepam were determined. The median number of seizures in all children on control days was 22 (range = 1-180) and, on days after low-dose clonazepam, the median was 6 (range = 0-73). The relative changes demonstrated a median of -70% (range from -100% to + 43%). A significant reduction of seizures (P = 0.0031) at median maximal plasma levels of clonazepam of 23 nmol/L (range = 11-41 nmol/L) was found. Thus in this study of the acute effects of a low-dose level of clonazepam on seizure frequency a significant reduction was found at plasma levels below those usually recommended. Inhibition of seizure activity seems to be achieved already at low plasma levels of clonazepam. These results suggest to start treatment at low doses of clonazepam and evaluate the individual effect carefully during dose escalation aiming at lowest possible dose with therapeutic effect. (C) 2003 by Elsevier Science Inc. All rights reserved.