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Published on: February 11, 2019
Chlorpromazine versus placebo for schizophrenia
C E Adams1, G Awad, J Rathbone
1Academic Unit of Psychiatry and Behavioural Sciences, Cochrane Schizophrenia Group, School of Medicine, University of Leeds, 15 Hyde Terrace, Leeds, UK, LS2 9LT. ceadams@cochrane-sz.org
The Cochrane Database of Systematic Reviews
|April 20, 2007
Summary
Chlorpromazine effectively reduces schizophrenia relapse and improves symptoms, but causes significant side effects like sedation and weight gain. This review quantifies its benefits and harms, supporting informed treatment decisions.
Area of Science:
- Psychiatry and Psychopharmacology
- Evidence-based medicine
- Clinical trial analysis
Background:
- Chlorpromazine, developed in the 1950s, is a foundational treatment for schizophrenia.
- Its long-standing use necessitates a quantitative evaluation of its efficacy and safety profile.
Purpose of the Study:
- To systematically evaluate the effects of chlorpromazine compared to placebo in schizophrenia treatment.
- To provide quantitative data on chlorpromazine's impact on relapse, overall improvement, and adverse events.
Main Methods:
- Conducted a comprehensive literature search of multiple databases and trial registers up to January 2007.
- Included 50 randomized controlled trials (RCTs) comparing chlorpromazine with placebo for schizophrenia.
- Analyzed dichotomous data using relative risk (RR) and calculated number needed to treat/harm (NNT/NNH).
Main Results:
- Chlorpromazine significantly reduces relapse rates in the short, medium, and long term (NNT=4 for long-term).
- It leads to global improvement in symptoms and functioning (NNT=6).
- Adverse effects include sedation (NNH=5), acute movement disorders (NNH=32), parkinsonism (NNH=14), dizziness (NNH=11), and weight gain (NNH=2).
Conclusions:
- Chlorpromazine remains a benchmark treatment for psychosis, with its efficacy supported by this quantitative review.
- Despite its benefits, chlorpromazine is associated with considerable adverse effects, highlighting its imperfect nature.
- This evidence supports informed, evidence-based decision-making for clinicians, patients, and caregivers regarding chlorpromazine use.
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