Prescribing Patterns and Potential Drug Interactions Among Patients With Heart Failure at Kenyatta National Hospital

Abstract

Background: Heart failure contributes significantly to the global disease burden. Patients with heart failure require multiple drugs, which predisposes them to potential drug-drug interactions. Therefore, improved prescription patterns and characterization of the potential drug-drug interactions are essential. Objective: To characterize the prescribing patterns and potential drug-drug interactions (pDDIs) for patients with heart failure at Kenyatta National Hospital (KNH). Methods: This was a cross-sectional study based at the KNH cardiac clinic. One hundred and twenty-four patients with heart failure were selected consecutively. Data collection started from 1st August 2021, which involved interviewing the patients and collecting data from their files during the clinic visit. The pDDIs were checked using the IBM Micromedex Drug interaction checker 2018 version. Data was analysed using STATA Version 13.0. Fischer’s or Pearson’s tests were done to identify an association between the independent variables such as the sociodemographic characteristics and pDDIs at p ≤ 0.05. Predictor variables of pDDIs were determined using bivariate and multivariate logistic regression model. Results: Most patients were female (n=68, 58.1%), married (n=97, 82.9%), Christians (n=115, 74.4%) and residing in the urban areas (n=65, 55.6%). The most widely prescribed drugs were beta-blockers (n = 81,76.9%), diuretics (n = 70, 71.8%), and mineralocorticoid receptor antagonists (n = 66, 56.4%). Each patient experienced an average of 2.05 pDDIs, with 156 (65.0%) being classified as major interactions. Possible outcomes of pDDIs included hyperkalaemia (n=57, 23.8%) and complete heart block (n=33, 13.8%). Having diabetes was associated with the development of a pDDI (p=0.040). Patients receiving an angiotensin converting enzyme inhibitors (p=0.012) or a beta-blocker (p=0.042) had a significant risk of developing a pDDI. The use of spironolactone was an independent predictor of the occurrence of a pDDI (AOR=26.0 (95% CI:5.2-135.4); p<0.001). .................................................................................................................................................................................................