Influence of Adverse Drug Reactions on Treatment Success: Prospective Cohort Analysis of HIV-Infected Individuals Initiating First-Line Antiretroviral Therapy in India

INTRODUCTION: Adverse drug reactions related to antiretroviral therapy (ART) remain a challenge in resource-limited settings, often causing significant morbidity and impaired adherence leading to treatment failure. This 2-year prospective study aimed to describe patterns and predictors of adverse reactions to first-line ART and assess the impact of these events on treatment success. METHODS: Between 2010–2013, 321 ART-naïve eligible adults were enrolled at two clinics in southern India. ART regimens included zidovudine or stavudine plus lamivudine, plus nevirapine or efavirenz. Pill count adherence, immunological and virological monitoring, and laboratory-based adverse drug reactions were measured prospectively and analyzed. RESULTS: Among 321 patients in the study, 289 (90.0%) patients experienced at least 1 adverse reaction, and 85 (26.5%) experienced at least 1 severe reaction. The incidence rate was 52 and 15 per 100 person-years for all reactions and severe reactions respectively. The cumulative incidence of zidovudine-induced anemia was 37.1% over 2 years. At 12 and 24 months, the proportion of patients with optimal adherence, undetectable viral load and CD4 counts >350 cells/mm(3) were similar between patients who experienced or did not experience severe adverse drug reactions. CONCLUSIONS: Our results highlight the high frequency of ART-related adverse drug reactions among individuals initiating first-line ART in India, underscoring the importance of detailed counseling and monitoring for maintaining ART durability. Severe drug-induced anemia needs to be addressed urgently with alternative first-line agents, and close laboratory surveillance. High treatment efficacy despite decreased drug safety seen here may be because patients have limited treatment options. Our results support the use of currently recommended safer first-line ART regimens that minimize the risk of severe life-threatening toxicities and provide for a better quality of life. TRIAL REGISTRATION: ISRTCN Registry: ISRCTN79261738.