Indication of an antipsychotic action of the opiate antagonist naloxone

Pharmakopsychiatr Neuropsychopharmakol. 1977 Sep;10(5):265-70. doi: 10.1055/s-0028-1094547.


In 20 psychotic patients with frequent hallucinations and/or actual delusional experience a possible antipsychotic action of the opiate antagonist naloxone (N-allyl-noroxymorphone) was investigated, using a double-blind placebo-controlled cross-over design. 18 of these patients were not treated with neuroleptic drugs; 13 suffered from an acute episode of schizophrenia. Psychopathological changes were assessed by the use of the IMPS-scale and of a symptom-specific rating scale (VBS). Intravenous injection of naloxone (in most cases 4.0 mg) induced a reduction of psychotic symptomatology (especially hallucinations) in the majority of patients. Compared with placebo this effect reached statistical significance within 2-7 hours after injection. From this result a possible involvement of endogenous ligands of opiate receptors in the pathogenesis of schizophrenia may be concluded.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Antipsychotic Agents*
  • Clinical Trials as Topic
  • Double-Blind Method
  • Female
  • Hallucinations / drug therapy
  • Humans
  • Male
  • Middle Aged
  • Naloxone / pharmacology*
  • Naloxone / therapeutic use
  • Placebos
  • Psychiatric Status Rating Scales
  • Psychotic Disorders / drug therapy
  • Psychotic Disorders / psychology
  • Time Factors


  • Antipsychotic Agents
  • Placebos
  • Naloxone