Predisposing factors for nevirapine toxicity among AIDS patients with low baseline CD4 count.

The objective of the study was to determine the predisposing factors and incidence of toxicity among AIDS patients treated with a nevirapine (NVP)-based regimen in clinical practice. A retrospective cohort study of representative samples of AIDS patients treated with a NVP-based regimen was performed. A total of 206 adult HIV/AIDS cases with median age (IQR) 33 years (range, 29-38 years), 51% male, treated between January 2004-December 2005, were included. Most (92.2%) of the patients were naïve to antiretroviral drug. The incidence of NVP toxicity was 1.09/100 person-months. The median onset time was 4 weeks post NVP initiation (2.57 weeks for skin toxicity and 12.43 weeks for hepatic toxicity). History of drug allergy and NVP toxicity were significantly associated (p = 0.006), as were sulfamethoxazole allergy and toxicity (p = 0.015). Regarding concomitant medication, concurrent anti-tuberculosis drugs significantly increased the risk of NVP associated liver toxicity (p = 0.001). Therefore, it is important to monitor adverse events from NVP, including liver function tests among HIV/AIDS patients with history of drug allergy, especially against sulfamethoxazole, and those concurrently treated with antituberculosis drugs.