Sex differences in nevirapine rash

Nevirapine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) that has the most common treatment limiting side effect of rash. Severe rash has been observed in 3% of patients taking nevirapine in clinical trials, 85% of whom were men. In a multicenter, retrospective cohort study of all patie nts who received nevirapine over a 5-year period, severe rash was noted in 9 of 95 women and 3 of 263 men (risk ratio [RR], 8.31; 95% confidence inter val [CI], 2.3-30.0; P=.005). Women were more likely to discontinue nevirapi ne therapy because of rash (RR, 4.5; 95% CI, 1.9-10.5; P=.0005). After adju sting for age and baseline CD4 cell count in multivariate analysis, women h ad a 7-fold increase in risk for severe rash and were 3.5 times more likely to discontinue nevirapine therapy. In women of reproductive age for whom c ontraception may occur, nevirapine remains the NNRTI of choice. Recognition of sex differences in this severe adverse event will be important in presc ribing nevirapine.