Medication-related problems in geriatric psychiatry-a retrospective cohort study

Information on medication-related problems (MRPs) in elderly psychiatric patients is scarce. In the present study, we analyzed the frequency and characteristics of MRPs in patients ≥60 years treated on the gerontopsychiatric ward of Hannover Medical School in 2019.

Taking advantage of an interdisciplinary approach, two independent investigators screened hospital discharge letters of 230 psychiatric inpatients for clinically relevant MRPs, followed by validation through an interdisciplinary expert panel. Drug interactions as a subset of MRPs were analyzed with the aid of two different drug interaction programs.

230 patients (63.0% female, mean age 73.7 ± 8.4 years, median length of stay 18 days) were prescribed a median of 6 drugs. In total, 2180 MRPs were detected in the study population and 94.3% of the patients exhibited at least one MRP. Patients displayed a median of 7 MRPs (interquartile range 3-15). Pharmacodynamic interactions accounted for almost half of all MRPs (48.1%; 1048/2180). The number of drugs prescribed and the number of MRPs per patient showed a strong linear relationship (adjusted R²  = 0.747).

An exceedingly high proportion of elderly psychiatric inpatients displayed clinically relevant MRPs in the present study, which may be explained by the multimorbidity prevalent in the study population and the associated polypharmacy. The number of drug interactions was largely in accordance with previous studies. As a novel finding, we detected that a considerable proportion of elderly psychiatric inpatients were affected by potential prescribing omissions, potentially inappropriate duplicate prescriptions, and insufficient documentation.