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.