Risperidone Versus Pimozide in Tourette's Disorder: A Comparative Double-Blind Parallel-Group Study

Background: The treatment of Tourette’s disorderwith classical neuroleptics is limited by their side effects.Risperidone is a new efficacious antipsychotic with a lowpropensity for extrapyramidal side effects. To establishrisperidone’s therapeutic potential in Tourette’s disorder, westudied the safety and efficacy of risperidone in comparison withpimozide in patients with Tourette’s disorder diagnosed accordingto DSM-III-R.

Method: In a 12-week, multicenter,double-blind, parallel-group study, 26 patients were treated withrisperidone (mean daily dose = 3.8 mg), and 24 patients weretreated with pimozide (mean daily dose = 2.9 mg).

Results: There was significantimprovement of tics with respect to the Tourette’s SymptomSeverity Scale (TSSS) for both groups. Forty-one patientscompleted the study. At endpoint, 54% (14/26) of the risperidonepatients and 38% (9/24) of the pimozide patients had only verymild or no symptoms on the global severity rating of the TSSS.Both treatment groups had improved significantly at endpoint inregard to Global Assessment of Functioning and Clinical GlobalImpressions scale outcomes. Symptoms of anxiety and depressivemood improved significantly from baseline in both groups.Obsessive-compulsive behavior improvement reached significanceonly in the risperidone group. Although the severity ofextrapyramidal side effects was low in both groups, fewerpatients in the risperidone group reported extrapyramidal sideeffects (N = 4) compared with the pimozide group (N = 8).Depression, fatigue, and somnolence were reported as the mostprominent side effects in both treatment groups.

Conclusion: Both drugs were efficaciousand well tolerated in patients with Tourette’s disorder.Risperidone may become the first-line drug in the treatment ofTourette’s disorder owing to a more favorable efficacy andtolerability profile.