Overview of the use of antiarrhythmic drugs at a tertiary hospital in Oman

Background: Antiarrhythmic drugs are commonly used to treat arrhythmia. However, data on the usage pattern of antiarrhythmic drugs, associated side effects, and the role of clinical pharmacist interventions in the Middle East are scarce. Objective: The purpose of this study was to describe the usage pattern, side effects, and clinical pharmacist interventions of antiarrhythmic drugs at the Sultan Qaboos University Hospital (SQUH), a tertiary care hospital in Oman. Methods: This retrospective observational study included adult patients (≥18 years) who received at least one dose of antiarrhythmic drugs at SQUH between January 2020 and December 2021. Ethical approval was obtained prior to conducting the study. Results: In total, 400 patients were enrolled in this study. Their mean age was 62.5 ± 16.6 years (range:19-96), and 55.3% (221/400) were male. Atrial arrhythmias were the most commonly observed (344/400, 86.0%). Beta-blockers (337/500, 67.4%) were the most prescribed class of drugs. The most commonly prescribed drugs were bisoprolol (263/400, 65.8%), carvedilol (65/400, 16.3%), and amiodarone (59/400, 14.8%). The majority of patients (300/400, 75.0%) received monotherapy, whereas 25% (100/400) received combination therapy. A total of 109 side effects were reported in 45 patients, resulting in an incidence rate of 11.3 %, with cardiovascular side effects accounting for the majority (41/109, 37.6%) of these. Amiodarone had the highest prevalence of adverse effects (33/109, 30.3%). A total of 122 clinical pharmacist interventions were observed in 13.0 % (52/400) of patients. Beta-blockers were associated with more than half of the interventions (61/122, 50.0%). Age (61.84 years vs. 66.75 years; p=0.047), comorbidities (83.6% vs. 96.2%; p=0.019), renal impairment (19.6% vs. 40.4%; p=0.001, heart failure (11.8% vs. 28.9%; p=0.002), concomitant medications (84.5% vs. 98.1%; p=0.004), polypharmacy (51.1% vs. 69.2%; p=0.022) and duration of therapy of less than one year (9.3% vs. 27.3%; p<0.001) was significantly associated with the need for intervention. Conclusion: Beta-blockers were the most commonly prescribed antiarrhythmic drugs in SQUH. Amiodarone was associated with the highest prevalence of side effects. Clinical pharmacy intervention at the SQUH was mainly related to antiarrhythmic drug selection and dose optimization.