Background:  The rate and severity of toxicity to HAART in pregnancy remains poorly understood. Recent information suggests that pregnant women may be at more risk of toxicity to nevirapine (NVP) therapy. To evaluate this observational cohort data has been interrogated to determine; the rate and severity of HAART-related complications in women treated with NVP- vs protease inhibitor (PI)-containing regimens in pregnancy; and if maternal characteristics or CD4 strata correlate with complications related to NVP use in pregnancy.

Methods:  Data were abstracted from a comprehensive observational HIV⁺ pregnancy cohort. Women who received any HAART therapy prior to delivery were included in the analysis. Severe toxicity was defined as any complication requiring discontinuation of drug. Analysis was done with SPSS.

Results:  From 1997 to 2003, 106 HIV⁺ pregnant women received HAART therapy in pregnancy. Of these 57 (53%) were treated with a NVP-based regimen and 49 (46%) were treated with a PI-based regimen. There were no significant differences between the NVP- vs the PI-treated women in terms of ethnicity, injection drug use during pregnancy, alcohol use, smoking status, or hepatitis C status. The CD4 at baseline in the NVP-treated group was similar to the PI-based regimens with the number of women with CD4 > 250 being 89.5% vs 82%, respectively. Of NVP-treated women, 10.5%, compared with 2% of PI-treated women, developed severe life-threatening toxicities. These included 2 Steven’s Johnstone syndrome, 2 hyperbilirubinemia/liver toxicity, and 2 rash/fever in the NVP group and 1 case of renal calculi in the PI group. In all women the symptoms and findings resolved completely on discontinuation of NVP. Of the women first starting NVP in pregnancy, 5 of 36 (13.9%) developed severe toxicity. There was no maternal to infant transmission of HIV in this cohort.

Conclusions:  In our cohort, the use of NVP in pregnancy resulted in much higher rates of severe toxicity than PI-based HAART regimens. Of note, the highest risk group was women starting NVP in pregnancy.

Keywords: nevirapine; toxicity; pregnancy