Antipsychotic properties of the partial dopamine agonist (-)-3-(3-hydroxyphenyl)-N-n-propylpiperidine(preclamol) in schizophrenia

Biol Psychiatry. 1998 Jan 1;43(1):2-11. doi: 10.1016/s0006-3223(97)00030-9.


Background: In an ongoing effort to characterize the clinical pharmacologic profile of the partial dopamine agonist (-)-3-(3-hydroxyphenyl)-N-n-propylpiperidine [(-)-3PPP], we administered it to drug-free schizophrenic patients in two consecutive studies.

Methods: In a preliminary dose-finding study, 9 patients were treated using a 6-week placebo-controlled crossover design. Then, to properly demonstrate the antipsychotic effect, we carried out an early efficacy study; here 10 patients received (-)-3PPP, 300 mg B.I.D., in a 1-week placebo-controlled crossover study.

Results: Dose-Finding Study: (-)-3PPP showed apparent antipsychotic effect in repeated dosing, with 300 mg B.I.D. being the most effective dose for antipsychotic action; however, the apparent antipsychotic action was not sustained for longer than 1 week, presumably because of desensitization of the receptor by the agonist. Early Efficacy Study: Positive symptoms as measured by the Psychosis Change Scale decreased in 1 week by 30% with (-)-3PPP compared to placebo, and negative symptoms measured with the Brief Psychiatric Rating Scale Withdrawal subscale decreased by 28% with the drug. In both studies, (-)-3PPP lacked any evidence of motor side effects.

Conclusions: These data show that psychotic symptoms decrease with (-)-3PPP and suggest that the treatment of schizophrenia with partial dopamine agonist is a promising strategy. Future attention will be directed toward testing techniques to diminish the tachyphylaxis to allow an ongoing therapeutic effect.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Antiparkinson Agents / adverse effects
  • Antiparkinson Agents / therapeutic use*
  • Antipsychotic Agents / adverse effects
  • Antipsychotic Agents / therapeutic use*
  • Cross-Over Studies
  • Dose-Response Relationship, Drug
  • Dyskinesia, Drug-Induced / physiopathology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Piperidines / adverse effects
  • Piperidines / therapeutic use*
  • Psychiatric Status Rating Scales
  • Schizophrenia / diagnosis
  • Schizophrenia / drug therapy*
  • Schizophrenic Psychology


  • Antiparkinson Agents
  • Antipsychotic Agents
  • Piperidines
  • preclamol