Psychotropic medication in geriatric psychiatric patients: use and unreported use in relation to serum concentrations.

PURPOSE: The aim of this observational study was to describe the type, number, and serum concentration levels of psychotropic drugs in elderly patients, on admission to a geriatric psychiatric inpatient unit. We further wanted to investigate the use and unreported use of psychotropic drugs by analyzing for a broad spectrum of drugs in the serum samples.
METHODS: A total of 236 patients were included. Drug use, patient characteristics, and diagnoses were recorded, and serum analysis was performed for a total of 56 psychotropic drugs in 233 of the patients.
RESULTS: Nine out of ten patients (88%) used one or more psychotropic drugs on admission to hospital; the mean use was 2.8 (95% confidence interval (CI) 2.6-2.9) drugs. In 25 patients (11%), drugs reported used were not detected in serum. Unreported use of drugs (serum analysis revealing one or more drugs not reported) was found in 100 patients (43%). This was more common in younger patients. Psychotropic polypharmacy (use of three or more psychotropic drugs) was found in 109 patients (47%). Patients with a main diagnosis of affective disorder used the most psychotropic drugs.
CONCLUSIONS: Psychotropic drugs are commonly used among geriatric psychiatric patients on admission to hospital. Psychotropic polypharmacy is a major concern among these patients. There was considerable unreported use of drugs within this population, and a low threshold for a broader serum analysis for psychotropic drugs appears indicated.