Background: High-dose antipsychotic regimes (defined as the prescription of more than 1000 chlorpromazine-equivalents
milligrams of antipsychotic per day) in the management of patients with schizophrenia
are not uncommon, but most reports are from western countries. Recent functional neuroimaging
studies have found that the previous notion concerning the use of antipsychotic medication,
especially in high doses, was unsupported and untenable. Methods: This international study examined the use of high dose antipsychotic medication and
its clinical correlates in schizophrenia patients within six East Asian countries/territories.
Results: Within the study group (n = 2399), 430 patients (17.9 %) were prescribed high dose
antipsychotics. Antipsychotic use varied significantly between countries, with Japan,
Korea, and Singapore using higher doses than the other countries. High dose antipsychotic
use was associated with younger age in Japan (p < 0.001), longer duration of admission
(p < 0.001), duration of illness (p < 0.001, particularly in Korea and Taiwan), positive
psychotic symptoms (p < 0.001, particularly in Japan and Korea), and aggression (p
< 0.05, particularly in Japan), and also with a higher likelihood of extrapyramidal
and autonomic adverse effects (p < 0.05, particularly in China). Country, younger
age, the presence of delusions and disorganized speech, polypharmacy, and receiving
depot medication but not atypical antipsychotic drugs were important predictors of
high antipsychotic use. Conclusions: This survey revealed that high antipsychotic dosing is not an uncommon practice in
East Asia. It behooves the prescribing clinicians to constantly reevaluate the rationale
for such a practice.
References
kang_sim@imh.com.sg
