Antipsychotic polypharmacy among elderly patients with schizophrenia and dementia during hospitalization at a Taiwanese psychiatric hospital.

BACKGROUND

This study was to investigate the prescribing patterns for antipsychotic drugs in elderly hospitalized patients with a diagnosis of schizophrenia or dementia at a psychiatric hospital in Taiwan from 2007 to 2012. This study also explored the predictors of antipsychotic polypharmacy (APP).

METHODS

We collected patients' demographic data, including year of admission, age, gender, and length of hospital stay, and drug-related information.

RESULTS

Second-generation antipsychotic (SGA) monotherapy was the most common type of therapy in both those with dementia and with schizophrenia, and quetiapine and risperidone were the most commonly prescribed drugs for these conditions, respectively. In late-life schizophrenia, 33.8% of the patients used first-generation antipsychotics (FGA) alone. Regarding APP, a combination of FGA and SGA and combinations of SGA were most commonly noted in schizophrenia patients and dementia patients, respectively. Overall, APP increased from 2007 to 2012. It was significantly more common in patients with dementia (odds ratio: 3.49, 95% confidence interval: 1.29-9.39, P = 0.014), less concurrent use of hypnotics and sedatives (odds ratio: 0.41, 95% confidence interval: 0.17-0.99, P = 0.046), and a higher-than-recommended dose of antipsychotic drugs (odds ratio: 4.98, 95% confidence interval: 2.75-9.02, P < 0.001).

CONCLUSIONS

FGA are still commonly used for the late-life schizophrenia at our hospital. Given their potentially hazardous side effects, FGA must be employed with caution. The use of APP involving SGA increased over the 6 years of the study period, especially among patients with dementia. However, the use of SGA in dementia began to decline after the US Food and Drug Administration's 2005 warning about SGA being associated with increased mortality in dementia patients, which contrasts with the trends examined in this study. Further controlled trials exploring the efficacy, safety, and tolerability of APP in this population are warranted to gain an additional insight into this practice.