Rates and correlates of pharmacotherapy-related problems among psychiatric inpatients: a representative Danish study

Background: Drug related problems (DRPs) occur frequently among psychiatric patients due
to common prescribing errors and complex treatment schedules. Clinical pharmacists (CPs)
are thought to play an important role in preventing DRPs and, consequently, to increasing the quality of inpatient care. There is, however, limited information available on DRPs within the psychiatric field in Denmark. The aim of this study was to identify rates and correlates
of pharmacotherapy-related problems among psychiatric inpatients in a Danish psychiatric
hospital.

Methods: A retrospective descriptive study was conducted by two CPs and data were obtained
from the medical records available in two psychiatric wards. Chart-reviews were conducted for the period of June 2015 to February 2017. The analyses focussed on the prevalence of DRP categories, implementation and acceptance rates, and drugs associated with the DRPs. Extracted data were discussed with the wards’ physicians and registered in a DRP-database.

Results: In total, 607 medical records were reviewed and, on average, 2.5 DRPs per
medication review were found. There was a positive correlation between the number
prescribed drugs and the average number of DRPs. The most frequent categories of DRPs
were ‘drug dosage’, ‘inappropriate drug’ and ‘interactions’. The drugs represented most
frequently in DRPs were olanzapine, quetiapine and pantoprazole. The overall acceptance rate
was 49% with 33% of those implemented clinically.

Conclusion: DRPs were commonly observed among psychiatric patients, particularly in those
with multiple prescriptions, in relation to drugs dosage, inappropriate prescriptions and drug
interactions. Particular attention must be paid to olanzapine, quetiapine and pantoprazole.
Strategies to minimise DRPs among psychiatric patients are warranted and CPs can play an
important role.