Fenfluramine treatment of twenty children with autism

The effects of fenfluramine were examined on 20 children with autism over a 48-week period utilizing a double-blind placebo-controlled crossover design. Blood and urine samples and psychological tests (Griffith's Developmental Scales and Real Life Rating Scale) were obtained at each crossover period. The only significant improvement was a decrease in abnormal motor behavior. We did not find any significant improvement in intellectual functioning or any correlation between good clinical response and low baseline serotonin levels or high baseline IQ. Serotonin decreased 53% after fenfluramine treatment and rebounded to a level 35% higher than baseline following a placebo period. Fenfluramine and the active metabolite norfenfluramine were determined in plasma samples.