Nevirapine Hypersensitivity

Approximately 7% of patients who commence nevirapine-containing antiretroviral therapy (ART) experience treatment-limiting rashes, hepatotoxicity, or both. Such hypersensitivity reactions (HSRs) tend to occur within the first 4 months of therapy and, in extremely rare cases, can be life threatening. High pretreatment CD4-cell counts are a known risk factor for nevirapine HSR, particularly among women. Consequently, the nevirapine package insert now contains a black box warning indicating that the drug should be avoided in women with CD4 counts >250 cells/mm³ and in men with CD4 counts >400 cells/mm³ (ACC Mar 1 2004). These recommendations, however, are based mostly on data from treatment-naive patients. Do they also apply to treatment-exper…