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:

• inappropriate medication
• polypharmacy
• drug interaction
• cardiovascular disease and elderly

Abbreviations

ACEi, angiotensin-converting enzyme inhibitors; ADE, adverse drug event; ADR, adverse drug reaction; AGS, American Geriatrics Society; AHA, American Heart Association; AOR, adjusted odds ratio; CCI, Charlson comorbidity index; CHS, College of Health Science; CI, confidence interval; CNS, central nervous system; COR, crude odds ratio; CVD, cardiovascular disease; DDI, drug-drug interaction; HR, hazard ratio; IPET, improving prescribing in the elderly tool; MAI, medication appropriateness index; NSAID, non-steroidal anti-inflammatory drug; OR, odds ratio; OTC, over the counter; PIDP, potentially inappropriate drug prescribing; PIMs, potentially inappropriate medications; PIP, potentially inappropriate prescribing; PP, polypharmacy; PPI, proton pump inhibitors; PPO, potential prescription omissions; SD, standard deviation; SPSS, Statistical Package for Social Sciences; START, Screening Tool of Older People’s Prescription; STOPP, Screening Tool to Alert Doctors to Right Treatment; TASH, Tikur Anbessa Specialized Hospital; TCA, tricyclic antidepressants; WHO, World Health Organization.

Data Sharing Statement

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Ethics Approval and Consent to Participate

Ethical approval was obtained from the Ethical Review Committee of the School of Pharmacy (ERB/SOP/315/13/2021), College of Health Sciences, Addis Ababa University. Then, patients, during follow up time, were briefed about the objectives of the study and the confidentiality of their information. In addition, they were informed of the right to abstain from participation in the study or to withdraw consent to participate at any time without reprisal. After ensuring that the patient has understood the information, the data collectors obtained written informed consent.

Acknowledgments

We want to acknowledge Addis Ababa University for giving us such an opportunity. In addition, we want to thank study participants and TASH management.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no competing interests.