Adverse drug reactions in adult medical inpatients in a South African hospital serving a community with a high HIV/AIDS prevalence: prospective observational study

AIMS To describe the frequency, nature and preventability of community-acquired and hospital-acquired adverse drug reactions (ADRs) in a South African hospital serving a community with a high prevalence of human immunodeficiency virus (HIV)/ acquired immunodeficiency syndrome. METHODS A 3-month prospective observational study of 665 adults admitted to two medical wards. RESULTS Forty-one (6.3%) patients were admitted as a result of an ADR and 41 (6.3%) developed an ADR in hospital. Many of the ADRs (46.2%) were considered preventable, although less likely to be preventable in HIV-infected patients than in those with negative or unknown HIV status (community-acquired ADRs 2/24 vs. 35/42; P < 0.0001; hospital-acquired ADRs 3/25 vs. 14/26; P = 0.003). Patients admitted with ADRs were older than patients not admitted with an ADR (median 53 vs. 42 years, P = 0.003), but 60% of community-acquired ADRs at hospital admission were in patients < 60 years old. Among patients < 60 years old, those HIV infected were more likely to be admitted with an ADR [odds ratio (OR) 2.32, 95% confidence interval (CI) 1.17, 4.61; P = 0.017]. Among HIV-infected patients, those receiving antiretroviral therapy (ART) were more likely to be admitted with an ADR than those not receiving ART (OR 10.34, 95% CI 4.50, 23.77; P < 0.0001). No ART-related ADRs were fatal. Antibiotics and drugs used for opportunistic infections were implicated in two-thirds of hospital-acquired ADRs. CONCLUSIONS ADRs are an important, often preventable cause of hospitalizations and inpatient morbidity in South Africa, particularly among the elderly and HIV-infected. Although ART-related injury contributed to hospital admissions, many HIV-related admissions were among patients not receiving ART, and many ADRs were associated with medicines used for managing opportunistic infections.