Psychotropic Polypharmacy and QT Prolonging Medications in Hospitalized Patients

It is common for patients with mental illnesses to be prescribed multiple psychotropic medications to effectively manage their conditions. Psychotropic polypharmacy has been shown to potentiate and increase the risks of several adverse effects, including QT prolongation. This study aimed to investigate the prescribing trends of and differences in prescribing of QT-prolonging medications (QTPMs) at admission and discharge in hospitalized patients. This retrospective observational study utilized inpatient data from three public hospitals between January and December 2019. QTPMs were classified according to the AZCERT classification. QTPMs doses were evaluated by calculating the ratio of prescribed daily dose (PDD) to the defined daily dose (DDD). Subgroup analyses showed significant differences between patient groups on admission and discharge (all p < 0.001). Mean QTPMs decreased significantly between the two time points only in patients admitted to acute medical and geriatric units (p < 0.001). PDD/DDD ratio for conditional risk QTPMs in acute mental health unit (AMHU) patients was increased at discharge (p = 0.038). Patients admitted to acute medical and geriatric units were four and eight times more likely to be discharged with one QTPM with known risk in combination with more QTPMs with conditional risk. Logistic regression showed significant relationships with age and total number of regular medicines at admission for those prescribed high-dose QTPMs at discharge. The findings underscore the necessity for enhanced monitoring of QTPMs in hospitalized patients, particularly for those at higher risk.