Adverse drug reactions in a cohort of Sri Lankan patients with non-communicable chronic diseases

Abstract

BACKGROUND: Adverse drug reactions (ADRs) pose a major problem in medication use. This study was done to describe incidence, nature and associated factors of ADRs in a cohort of Sri Lankan patients with non-communicable chronic diseases (NCCDs). METHODS: The prospective observational data presented here are obtained as a part of a large study conducted in a tertiary-care hospital in Sri Lanka. In-ward patients with NCCDs were recruited systematically using the admission register in the ward as the sampling frame. All ADRs occurred during the index hospital admission and 6-month post-discharge period were detected by active surveillance. RESULTS: 715 patients were studied (females – 50.3%; mean age – 58.3±15.4years). 35.4% were aged ≥65years. Mean number of drugs prescribed per patient was 6.11±2.97. Most prevalent NCCDs were hypertension (48.4%), diabetes (45.3%) and ischemic heart disease (29.4%). 154 ADRs [33 (21.4%) during index hospital admission; 121 (78.6%) during 6-month post-discharge period) were detected involving 112 (15.7%) patients. 51.9%(80/154) of them were potentially avoidable. 47% (73/154) of ADRs were serious adverse events (SAEs); 13 were life threatening, 46 caused hospitalization and 14 caused disability. The most common causes for re-hospitalization due to ADRs were hypoglycemia due to anti-diabetic drugs (17/46), bleeding due to warfarin (6/46) and hypotension due to anti-hypertensives (6/46). ADRs were more common in elderly (34% vs 14.7%, p<0.001), in those who were on ≥5 drugs (25.9% vs 12.7%, p<0.001) and among those with diabetes (28.5% vs 15.6%, p<0.001). CONCLUSIONS : Incidence of ADRs was high in the study population. A large proportion of them were SAEs. The majority of ADRs that required re-hospitalization were caused by widely used drugs and were potentially avoidable. Factors associated with a higher incidence of ADRs were age ≥65years, ≥5drugs in the prescription and presence of diabetes. The healthcare system in the study setting needs improvement in order to minimize ADRs.