Medication Appropriateness, Polypharmacy, and Drug-Drug Interactions in Ambulatory Elderly Patients with Cardiovascular Diseases at Tikur Anbessa Specialized Hospital, Ethiopia

Abstract

Background: Appropriate prescribing is often challenging in geriatric patients due to age-related pharmacokinetic and pharmacodynamic alterations. Elderly patients with cardiovascular diseases are frequently prescribed multiple medications. Hence, it is imperative to investigate medication appropriateness, polypharmacy, and drug-drug interactions in these groups of patients.

Objective: To assess medication appropriateness using the 2019 American Geriatric Society Beers and Medication Appropriateness Index criteria, polypharmacy and drug-drug interactions among elderly ambulatory patients with cardiovascular diseases at Tikur Anbessa Specialized Hospital.

Methods: A hospital-based retrospective cross-sectional study was conducted among 384 elderly (60 years and older) ambulatory patients with cardiovascular diseases between May 01-August 30, 2021. Data was collected from the patient's medical record using a data abstraction tool. The data were entered and analyzed using the SPSS program. Descriptive and logistic regression models were used to present the findings.

Results: The most frequent diagnosis was hypertension (78.4%) followed by ischemic heart disease (31.3%). Averagely, 4.4 ± 2 medications were prescribed per patient. More than half of (53.1%) the patients received polypharmacy. According to Beer's and medication appropriateness index criteria, over one-third (28.1%) and the majority (95.1%) of the patients were prescribed potentially inappropriate medications, respectively. In addition, 53.1% and 90.1% of patients had polypharmacy, and were exposed to potential drug-drug interactions ranging from mild to major interactions, respectively. Further, polypharmacy was significantly associated with inappropriate medication prescribing.

Conclusion: The study found that more than half of the patients got one or more potentially inappropriate medications in both criteria. The medication appropriateness index tool identified more potentially inappropriate medication than the Beers criteria. In addition, more than half of the patients got polypharmacy and had potential drug-drug interactions. Further, polypharmacy was significantly associated with inappropriate medication prescriptions. These findings highlight the need for interventions to improve appropriate prescribing practice among elderly patients.

Keywords: cardiovascular disease and elderly; drug interaction; inappropriate medication; polypharmacy.

Figure 1

Inappropriate drug classes based on the AGS Beers criteria.