A randomized controlled trial of allopurinol vs. placebo added on to antipsychotics in patients with schizophrenia or schizoaffective disorder

Schizophr Res. 2012 Jun;138(1):35-8. doi: 10.1016/j.schres.2012.02.014. Epub 2012 Apr 4.

Abstract

Adenosine agonists produce behavioral effects similar to dopamine antagonists, hence increasing adenosine levels might improve symptoms of schizophrenia. This hypothesis is supported by three single-site studies indicating that allopurinol, which increases adenosine levels, improved symptoms in patients with schizophrenia. We performed a multi-center, 8-week RCT of allopurinol vs. placebo added to anti-psychotic medications in 248 patients with schizophrenia or schizoaffective disorder. Both groups showed improvement in the PANSS (effect size 1.13) and in clinical and cognitive measures. No difference was observed between groups in primary (t=0.01, p=0.992) or secondary outcome measures. These findings do not support allopurinol as a treatment for schizophrenia.

Trial registration: ClinicalTrials.gov NCT00864825.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / metabolism*
  • Adult
  • Allopurinol / therapeutic use*
  • Antipsychotic Agents / therapeutic use*
  • Drug Therapy, Combination
  • Enzyme Inhibitors / therapeutic use*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Psychotic Disorders / drug therapy*
  • Schizophrenia / drug therapy*
  • Treatment Outcome
  • Xanthine Oxidase / antagonists & inhibitors*

Substances

  • Antipsychotic Agents
  • Enzyme Inhibitors
  • Allopurinol
  • Xanthine Oxidase
  • Adenosine

Associated data

  • ClinicalTrials.gov/NCT00864825