The effects of the atypical
neuroleptic clozapine were studied in an inbred line of Syrian golden hamsters with generalized
dystonia, i.e. a frequent
movement disorder in humans. The effects of
clozapine were compared with those of the classical
neuroleptic,
haloperidol.
Clozapine, 7.5-20 mg/kg i.p., potently reduced the severity of dystonic attacks in the mutant hamster model, but induced marked sedation at these doses. Lower doses were ineffective.
Haloperidol, 0.5 mg/kg i.p., significantly reduced the severity of
dystonia without marked sedation. The finding that
clozapine possesses antidystonic potency similar to that of
haloperidol in a genetic model of
dystonia might suggest that this atypical
neuroleptic is an effective alternative in the treatment of dystonic patients who respond to
neuroleptics, particularly because of the clinical evidence that
clozapine is almost devoid of extrapyramidal adverse effects.