A six month randomized controlled trial of long acting injectable risperidone 50 and 100 mg in treatment resistant schizophrenia

H. Y. Meltzer*, J. P. Lindenmayer, J. Kwentus, D. B. Share, R. Johnson, K. Jayathilake

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


It has been suggested that atypical antipsychotic drugs (A-APDs) other than clozapine may be effective to improve positive symptoms in some patients with treatment resistant schizophrenia (TRS), if both the dose is higher, and the duration of the trial longer, than those which have been ineffective in non-TRS (NTRS) patients. This hypothesis was tested with long acting injectable risperidone (Risperdal Consta®, RLAI). One hundred sixty TRS patients selected for persistent moderate-severe delusions or hallucinations, or both, were randomized to RLAI, 50 or 100. mg biweekly, in a six month, outpatient, double-blind, multicenter trial. We hypothesized that RLAI, 100. mg, would be more effective than RLAI, 50. mg. However, both doses produced clinically significant and equivalent improvement in PANSS Total, Positive, and Negative subscale scores, as well as key cognitive, global and functional measures, with increasing response during the course of the study, confirming the value of longer clinical trial duration for patients with TRS, but not superiority of the higher dose. The overall response rate was comparable to that previously reported for clozapine and high dose olanzapine, another A-APD, in TRS. Both doses of RLAI were equally well tolerated, producing minimal extrapyramidal side effects and few drop outs. Plasma levels of the active moiety, risperidone. +. 9-hydroxyrisperidone, during treatment with RLAI 100. mg, were comparable to those for 6-8. mg/day oral risperidone, which have not been effective in TRS. Further study of RLAI, ≥. 50-100. mg biweekly, should compare it with clozapine and oral risperidone in TRS, with duration of treatment ≥. six months.

Original languageEnglish (US)
Pages (from-to)14-22
Number of pages9
JournalSchizophrenia Research
Issue number1-3
StatePublished - Apr 2014


  • Extrapyramidal
  • Long acting injectable
  • Prolactin
  • Risperidone
  • Schizophrenia
  • Treatment resistant

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry

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