Antipsychotic polypharmacy in patients with schizophrenia: a multicentre comparative study in East Asia

Abstract

AimsPrevious studies of the prescription patterns of psychotropic medications in patients with schizophrenia have highlighted a high rate of antipsychotic polypharmacy, but data in Asia are sparse. This study seeks to examine the prevalence of antipsychotic polypharmacy in patients with schizophrenia and compare the differences between patients receiving one vs. those receiving more than one antipsychotic. MethodsAntipsychotic prescription for a sample of 2399 patients with schizophrenia from six countries and territories was evaluated. Daily doses of antipsychotic medications were converted to standard chlorpromazine equivalents (CPZ). ResultsAntipsychotic polypharmacy was found in 45.7% ( n = 1097) of the patients with wide intercountry variations. Polypharmacy was associated with male gender [odds ratio (OR) 1.24, 95% confidence interval (CI) 1.06, 1.46, P < 0.01], advanced age ( t = -7.81, d.f. = 2396, P < 0.001), psychiatric hospital setting (OR 1.34, 95% CI 1.11, 1.62) as well as higher daily CPZeq doses (411.47 vs. 983.10 CPZeq day -1 , z = -25.94, P < 0.001), anticholinergic use (OR 3.17, 95% CI 2.65, 3.79, P < 0.001) and less use of an atypical antipsychotic drug (OR 0.83, 95% CI 0.71, 0.98, P < 0.05). On multivariate analysis, country, age and duration of illness were significantly associated with antipsychotic polypharmacy. ConclusionThis study highlighted the wide intercountry variations of antipsychotic polypharmacy which are likely to be influenced by a complex combination of clinical, setting, cultural and personal practice factors, requiring more research.

Thirty years of scientific research on second-generation antipsychotic drugs in Japan: A bibliometric analysis

“…Besides the differences in antipsychotic prescribing patterns between Japan and other countries [25,26], we also found in this study that the research paper productivity on SGAs was different from Japan to other Asian countries/areas such as Taiwan [11]. But we trust that research in this field will possibly continue to grow in the coming years, bearing in mind that the ideal antipsychotic drug has not yet been found [5] and that etiopathogeny of schizophrenia is still mostly unknown.…”

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“…The rate of polypharmacy (>4 medications) in this aforementioned country is high. Sim et al (2004) found polypharmacy to occur at a rate of 45.7 % in elderly and chronically ill patients 28 . Singapore researchers have reported the rate of polypharmacy in their people to be 59% in previous years and 73% in 2000 29 .…”

“…Sim et al (2004) found polypharmacy to occur at a rate of 45.7 % in elderly and chronically ill patients 28 . Singapore researchers have reported the rate of polypharmacy in their people to be 59% in previous years and 73% in 2000 29 . By studying the literature, we were encouraged to examine the benefits of replacing polypharmacy with a single medication in elderly patients with chronic schizophrenia.…”

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