ALLOPURINOL AS ADD-ON THERAPY IN REFRACTORY EPILEPSY - A DOUBLE-BLINDPLACEBO-CONTROLLED RANDOMIZED STUDY

The antiepileptic effect of allopurinol was assessed in a double-blind , randomized, placebo-controlled, cross-over trial in 84 patients with epileptic seizures refractory to standard antiepileptic drugs (AEDs). During a retrospective baseline period, patients experienced at least four seizures of any type per month. The effects of allopurinol and m atching placebo were examined for 4-month periods. Allopurinol dosage was 150 mg daily for children weighing <20 kg and 300 mg daily for oth er patients. Efficacy analysis based on the Wilcoxon rank-sum test was conducted for the 80 patients who completed the study. No significant period effect or treatment-period interaction was noted. Allopurinol significantly reduced total seizures (p = 0.005), and secondarily gene ralized seizures (p = 0.0015). Median seizure reduction for total seiz ures was 10.5 and 27.9% for secondarily generalized seizures. Subjecti ve preferences by clinicians evaluated blindly significantly favored a llopurinol. No significant change occurred in the plasma concentration of concomitant AEDs between treatment periods, but serum urate decrea sed by 32% during allopurinol treatment. No clinically relevant side e ffects or changes in routine laboratory clinical chemistry or hematolo gy were ascribed to allopurinol.