Expanded therapeutic range of valproate.
Twenty-five pediatric patients with serum valproate levels above 100 micrograms/ml (therapeutic range: 50-100 micrograms/ml) are reviewed for nondose-related side effects and seizure control. The dose of valproate varied from 50-100 mg/kg/day. All patients had generalized or mixed seizure disorders which were difficult to control. Seizure frequency decreased by more than 50% in 14 patients. For those patients with improved control, valproate levels ranged from 111-196 micrograms/ml. Patients were carefully monitored for side effects; nondose-related side effects were not encountered. Random valproate levels were between 100-200 micrograms/ml. The clinical response to valproate can be augmented by increasing it to the maximum tolerated dose.