Low dose of clozapine in the treatment of dopaminergic psychosis in Parkinson's disease

Clin Neuropharmacol. 1997 Jun;20(3):204-9. doi: 10.1097/00002826-199706000-00003.


Dopaminergic psychosis frequently complicates the pharmacological treatment of Parkinson's disease. Dose reduction of dopaminomimetic therapy or treatment with conventional neuroleptics improves psychosis but worsens parkinsonism. In an open-label 12-month trial, the clinical antipsychotic efficacy of the atypical neuroleptic clozapine was investigated in 36 parkinsonian patients (age range 46-85 years) with symptoms of dopaminergic psychosis including delusions, vivid dreams, hallucinations, frank paranoid delirium, and hypersexuality. Clozapine, given orally at bedtime, was started at a dose of 6.25 mg and titrated upward to the minimal effective dose. In all patients, psychosis responded to very low clozapine doses (mean 10.59 +/- 6.48 mg/day). Clozapine doses correlated with the severity of psychosis. During clozapine treatment, parkinsonian disabilities and levodopa dosage remained statistically unchanged. During the 12-month study, no patient had clozapine-induced agranulocytosis or other severe side effects. These findings indicate that even at low doses, clozapine effectively controls dopaminergic psychosis in Parkinson's disease patients without compromising motor function.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antipsychotic Agents / administration & dosage
  • Antipsychotic Agents / therapeutic use*
  • Clozapine / administration & dosage
  • Clozapine / therapeutic use*
  • Delusions
  • Dopamine / adverse effects*
  • Female
  • Hallucinations
  • Humans
  • Male
  • Middle Aged
  • Parkinson Disease / complications
  • Parkinson Disease / drug therapy*
  • Psychoses, Substance-Induced / drug therapy*


  • Antipsychotic Agents
  • Clozapine
  • Dopamine