Reducing the dose of antipsychotic medications for those who had been treated with high-dose antipsychotic polypharmacy: An open study of dose reduction for chronic schizophrenia

Takefumi Suzuki, Hiroyuki Uchida, Kenji F. Tanaka, Masayuki Tomita, Kenichi Tsunoda, Kensuke Nomura, Harumasa Takano, Akira Tanabe, Koichiro Watanabe, Gohei Yagi, Haruo Kashima

Research output: Contribution to journalArticle

30 Citations (Scopus)


Antipsychotic medications are often used at higher than the recommended dose and sometimes in a combination regimen to treat schizophrenia. However, in general, high-dose therapies have been abandoned in recent clinical studies. In this study, dose reduction of antipsychotic medication was implemented for patients with chronic schizophrenia, most of whom (81%) had been treated with an antipsychotic high-dose polypharmacy regimen consisting of more than 1000 mg/day in total amount. The results show that merely reducing the amount of antipsychotic led to favourable outcome in 23 out of 41 cases (56%), with another 13 cases (32%) showing no change. Dose reduction ended in failure in only five subjects (12%). Overall, the amount as well as the number of antipsychotic medications was significantly reduced from 1984 mg to 812 mg per day (reductions of 59% and from 3.6 to 2.2, respectively; both P<0.0001). The Global Assessment of Functioning scale improved from 30.6 to 37.2, which reached significance (P<0.001). Accordingly, the Severity of Illness improved from 4.7 to 4.2, and was also significant (P<0.01). Dose reduction is an encouraging strategy to consider for those patients with schizophrenia who have chronically been treated with high-dose antipsychotic polypharmacy, even if judged unavoidable in the past.

Original languageEnglish
Pages (from-to)323-329
Number of pages7
JournalInternational clinical psychopharmacology
Issue number6
Publication statusPublished - 2003 Nov 1



  • Antipsychotics
  • Dose reduction
  • High-dose therapy
  • Polypharmacy
  • Schizophrenia

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Pharmacology (medical)

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