Third-Trimester Maternal Toxicity With Nevirapine Use in Pregnancy

OBJECTIVE Nevirapine-based therapy is associated with increased frequency of adverse events among women with CD4+ cell count of 250 cells/microL or greater. We evaluated the safety of nevirapine-based antiretroviral therapy in human immunodeficiency virus (HIV)-1-infected pregnant women. METHODS We retrospectively evaluated 23 pregnancies managed with nevirapine-based regimens from July 2001 to April 2005. The incidence of adverse events was determined and analyzed by CD4+ cell count of either less than or greater than or equal to 250 cells/microL, and gestational age when nevirapine was initiated. Liver function abnormality was graded according to the National Institute of Allergy and Infectious Diseases Division of AIDS toxicity guidelines. RESULTS Five of 23 patients (21.7%) started nevirapine-based therapy after 27 weeks of gestation. All 3 cases of adverse events occurred in this group within 6 weeks of initiating therapy and with CD4+ cell count greater than 250 cells/microL. A significant difference was noted in the proportion of patients who developed toxicity while starting nevirapine in the third trimester (3/5, 60%; 95% confidence interval 14.66-94.73) compared with those starting nevirapine earlier in pregnancy (0/18, 0%; 95% confidence interval 0.0-18.53; P < .006). Two patients developed rash, eosinophilia, and liver function abnormality, with one developing clinical hepatitis and renal failure. A third patient had abnormal elevation of liver enzymes but was asymptomatic. CONCLUSION The incidence of adverse events with nevirapine may be lower than previously reported (13% versus 29%) and may be primarily noted with initiating the drug late in pregnancy. Further study of nevirapine in larger cohorts of HIV-infected pregnant women is warranted to determine the relationship between nevirapine hepatotoxicity and trimester use. LEVEL OF EVIDENCE II-3.