Polypharmacy and psychotropic drug loading in patients with schizophrenia in Asian countries: Fourth survey of Research on Asian Prescription Patterns on antipsychotics

Aim The aim of the present study was to survey the prevalence of antipsychotic polypharmacy and combined medication use across 15 Asian countries and areas in 2016. Methods By using the results from the fourth survey of Research on Asian Prescription Patterns on antipsychotics, the rates of polypharmacy and combined medication use in each country were analyzed. Daily medications prescribed for the treatment of inpatients or outpatients with schizophrenia, including antipsychotics, mood stabilizers, anxiolytics, hypnotics, and antiparkinson agents, were collected. Fifteen countries from Asia participated in this study. Results A total of 3744 patients' prescription forms were examined. The prescription patterns differed across these Asian countries, with the highest rate of polypharmacy noted in Vietnam (59.1%) and the lowest in Myanmar (22.0%). Furthermore, the combined use of other medications, expressed as highest and lowest rate, respectively, was as follows: mood stabilizers, China (35.0%) and Bangladesh (1.0%); antidepressants, South Korea (36.6%) and Bangladesh (0%); anxiolytics, Pakistan (55.7%) and Myanmar (8.5%); hypnotics, Japan (61.1%) and, equally, Myanmar (0%) and Sri Lanka (0%); and antiparkinson agents, Bangladesh (87.9%) and Vietnam (10.9%). The average psychotropic drug loading of all patients was 2.01 ± 1.64, with the highest and lowest loadings noted in Japan (4.13 ± 3.13) and Indonesia (1.16 ± 0.68), respectively. Conclusion Differences in psychiatrist training as well as the civil culture and health insurance system of each country may have contributed to the differences in these rates. The concept of drug loading can be applied to other medical fields.