Adverse drug reactions reported to a provincial public health sector pharmacovigilance programme in South Africa

Abstract

Background: There are limited data in South Africa (SA) on adverse drug reaction (ADR) patterns and common causative medicines, outside of HIV and tuberculosis treatment programmes. In SA, Western Cape Province has a pharmacovigilance programme that collects spontaneous reports of suspected ADRs from public sector healthcare facilities.

Objectives: To describe reports received by the pharmacovigilance programme over a 4-year period (excluding those ascribed to medicines used to treat HIV and tuberculosis), as well as challenges faced in the implementation of such a system.

Methods: Reports of suspected ADRs and deaths possibly related to ADRs received between January 2015 and December 2018 were reviewed. Causality was assessed by a pharmacist, with multidisciplinary team involvement for all deaths and complicated cases. Causality was categorised according to the World Health Organization-Uppsala Monitoring Centre system. Preventability was assessed using Schumock and Thornton criteria. Observations on preventability and challenges faced in the operation of a spontaneous reporting system were also noted.

Results: We received 5 346 reports containing 6 023 suspected ADRs. There were 5 486 ADRs confirmed after causality assessment, in 5 103 reports. Cough, angio-oedema, movement disorders and uterine bleeding disorders were the most common ADRs. Enalapril, etonogestrel, amlodipine and hydrochlorothiazide were the most commonly implicated drugs. Seven deaths were reported; 3 of these reports of deaths had confirmed ADRs, and these ADRs were assessed as contributing to the deaths. Approximately 3.8% of commonly reported ADRs were preventable.

Conclusions: Enalapril and etonogestrel were responsible for a significant proportion of ADRs reported to this provincial programme. Future work should include quantification of preventability aspects to better inform gaps in healthcare worker knowledge that can be addressed in order to improve patient care.