Pimozide is a neuroleptic drug with dopamine receptor and calcium channel blocking activity that is used in the treatment of Tourette's syndrome. A comparison of the pharmacokinetics of pimozide was made in children and adults with Tourette's syndrome. Seven adults (ages 23-39) and four children (ages 6-13) received a single 2-mg oral dose of pimozide and a minimum of nine blood samples were collected over a four-day period. Mean elimination half-life of pimozide in children was 66 hours compared with 111 hours in adults with Tourette's syndrome. Significant interindividual variability of pimozide pharmacokinetics was found in both adults and children with Tourette's syndrome. The pharmacokinetics of pimozide in patients with Tourette's syndrome differs from that reported in adult populations with chronic schizophrenia.