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.