Incidence of hospitalised hypokalaemia in patients with indapamide prescription: a population-based study

Abstract

Introduction: Indapamide is a commonly prescribed thiazide diuretic for treating hypertension. In the literature, 40% of patients receiving diuretics experience hypokalaemia. We investigated the incidence of hypokalaemia as a cause of admission to public hospitals in Hong Kong. Methods: Adult patients aged ≥20 years who had a prescription of indapamide for >180 days from 1 January 2006 to 31 December 2017 were identified using the Clinical Data Analysis and Reporting System. Patients who had hypokalaemia before indapamide prescription were excluded. They were followed until hospitalisation for hypokalaemia, death or end of prescription. Results were analysed using R version 3.6.0. The incidence and 95% confidence interval (CI) were estimated. These were further adjusted for age, or age and sex. Results: Altogether, 97 878 patients were included with 226 098 person-years of observation. The incidence of hospitalised hypokalaemia was 24.3 (95% CI=22.7-26.1) per 10 000 person-years. The age-adjusted as well as ageand-sex-adjusted incidences were 25.1 (95% CI=23.3-27.0) and 24.9 (95% CI=23.2-26.8) per 10 000 person-years, respectively. Female had higher incidence than male (incidence rate ratio=1.40, 95% CI=1.29-1.52). No patients died of hypokalaemia during admission. Conclusions: Indapamide-induced hypokalaemia requiring hospitalisation is uncommon, which may be due to awareness of this common adverse effect. By monitoring blood electrolytes, emergency admissions and fatalities arising from drug-induced hypokalaemia can be avoided.