Objective: To evaluate a treatment strategy of substituting zidovudine (ZDV) for stavudine (d4T)-based highly active antiretroviral therapy (HAART), aimed at preventing d4T-associated toxicity, in a programmatic setting in rural Cambodia.
Methods: Survival probability, CD4 gain, anemia incidence, and factors associated with severe anemia were analyzed in a cohort of adult patients switched from d4T- to ZDV-containing regimens from March 2006 to March 2007.
Results: Among 527 patients systematically switched to ZDV after d4T-based HAART for a median of 18 months, 4 (0.8%) patients died, 2 (0.4%) were lost to follow-up, 18 (3.4%) were transferred out, and 503 (95.4%) remained on HAART. Median CD4 gain was +263.5 cells/microL (interquartile range: 89.25-369.5) at 24 months. Within 1 year after the switch, 21.9% and 7.1% of patients developed anemia (grades 1-4) and severe anemia (grades 3-4), respectively. Low body mass index (< or =18) and low CD4 count (<200 cells/microL) at the time of switch were factors associated with severe anemia. Additional follow-up visits for laboratory monitoring and adherence counseling, increased absenteeism from work, and transportation costs for the patients were noted.
Conclusions: The switch strategy of substituting ZDV for d4T-based HAART led to satisfactory overall clinical outcomes. However, it resulted in a relatively high incidence of mild to severe anemia and increased burden for the program and the patients.