A Study on Polypharmacy in the Elderly Psychiatric Outpatients with Persistent Treatments for 3 years

ABSTRACT

OBJECTIVES: The objective of this study was to investigate the prescription trends for the elderly psychiatric outpatients at a university hospital. METHODS: We performed a retrospective study based on medical records. Data on 146 elderly patients (65 years and older) diagnosed with psychiatric disorders according to ICD-10 from January 2005 to March 2008 were collected. Analyses were performed regarding demographic characteristics, prevalence of polypharmacy, and the doses and types of drugs prescribed. RESULTS: In 146 subjects, the mean age was 76.14+/-5.21. More than five types of drugs were prescribed to 49.5% of the patients in 2008. The percentage of stable users (those without changes in the category of polypharmacy for 3 years) was 69.8%. Each patient received an average of 4.20+/-1.50 kinds of drugs in 2005 and 4.02+/-1.77 in 2008. The average dose of drugs was 6.1+/-3.50 in 2005 and 6.49+/-4.09 in 2008, and the difference was not statistically significant. The average number of types of psychiatric drugs prescribed to the patients decreased from 2.37+/-0.86 in 2005 to 2.17+/-0.87 in 2008 (p<0.05). CONCLUSION: Although practice of polypharmacy showed a slow increase over the 3 years from 2005 to 2008, almost half of the elderly patients we studied received multiple drugs. Since polypharmacy can increase drug-drug interactions and adverse effects in the elderly, appropriate drug monitoring and careful prescription are necessary.