Valproic Acid in Childhood Epilepsy: Anticonvulsive Efficacy in Relation to Its Plasma Levels

The study monitored plasma levels of valproic acid in 90 epileptic children over two years. Among 34 patients on sodium valproate monotherapy, 82% achieved complete seizure control with a mean plasma level of 65.1 micrograms/ml, while 18% experienced recurring seizures with higher plasma levels, suggesting resistance to the drug. Valproic acid was effective for absences, tonic-clonic seizures, and partial epilepsy. In combination with phenobarbital, 64% of 22 children achieved seizure control. In more severe cases treated with multiple anticonvulsants, only 35% achieved control. Side effects included increased appetite, gastrointestinal disturbances, transient hair loss, and tiredness, mostly at plasma levels above 70 micrograms/ml. A therapeutic range of 40-90 micrograms/ml was suggested.