Double-blind placebo-controlled trial of flunarizine as add-on therapy in refractory childhood epilepsy

Abstract

Flunarizine (FLN) has been suggested as an add-on treatment in drug-resistant epilepsy patients. In view of the discordant experiences and of the paucity of controlled trials in children, we studied its effectiveness in 20 patients aged 6 to 18 years (10 males and 10 females), affected by drug-resistant epilepsy. 14 had symptomatic generalized epilepsy (the Lennox-Gastaut syndrome in 10; other forms in 4); 3 had cryptogenic generalized epilepsy (the Lennox-Gastaut syndrome in 2; myoclonic absences epilepsy in 1); 3 had symptomatic partial epilepsy (temporal lobe epilepsy). 7 of them were withdrawn: only 1 because of side effects. An initial four-month baseline pretrial period was followed by two four-month periods of administration of FLN or a placebo, under double blind conditions, in a randomized sequence. Preexisting antiepileptic (AEDs) medication was maintained at a constant dose throughout the study. FLN was administered as drops in a single evening dose of 5 mg (patients less than 10 years) or 10 mg. (patients greater than 10 years). During the pretrial phase, after phase 1 and phase 2, a waking EEG was recorded and blood samples were taken for hematology, hepatic-function tests, and AED serum levels. The evaluation of the activity of FLN was based on the total number of seizures. A 30-60% reduction in seizure frequency was found in 5 out of the 13 patients completing the trial (no changes occurred in the remainders). This result did not appear to be due to changes in the plasma levels of the AEDs. No significant differences were seen in the EEG paroxysmal activity in the three phases of the study. Side effects were rare. The serum FLN levels ranged between 16.4 and 109 ng/ml. It seems that the antiepileptic properties of FLN need further validation, particularly in childhood.