Pimozide (3.4 mg/day) and haloperidol (3.5 mg/day) therapy for Tourette syndrome were compared in a double-blind, 24-week, placebo-controlled crossover study of 22 patients, aged 7-16 years, at the Institute of Psychiatry, Charleston, SC. A 70% tic reduction was obtained in 64% of patients during either drug treatment, compared to 23% of patients with placebo. The effect of pimozide was significantly superior to that of placebo on total TS Global Scale scores, whereas the effect of haloperidol failed to reach statistical significance. Extrapyramidal side effects were more frequent with haloperidol than pimozide. Treatment-limiting side effects, depression, anxiety, severe dyskinesias, occurred in 41% of the 22 patients during haloperidol treatment, a threefold higher frequency than with pimozide. [1]

COMMENT. Pimozide is superior to haloperidol in therapeutic efficacy in children and adolescents with Tourette syndrome, and the incidence of extrapyramidal side effects is significantly lower. Only severe cases with a Tourette Symptom Global Scale score greater than 20 were included in the above trial, and exclusion criteria included: serious medical illness, abnormal ECG, use of other concurrent medication for asthma or ADHD (eg. theophylline, stimulants).