Effectiveness of Non-nucleoside Reverse-Transcriptase Inhibitor-Based Antiretroviral Therapy in Women Previously Exposed to a Single Intrapartum Dose of Nevirapine: A Multi-country, Prospective Cohort Study

Citation:
"Effectiveness of Non-nucleoside Reverse-Transcriptase Inhibitor-Based Antiretroviral Therapy in Women Previously Exposed to a Single Intrapartum Dose of Nevirapine: A Multi-country, Prospective Cohort Study."; 2010.

Abstract:

Intrapartum and neonatal single-dose nevirapine (NVP) reduces the risk of mother-to-child HIV transmission
but also induces viral resistance to non-nucleoside reverse transcriptase inhibitor (NNRTI) drugs. This drug resistance largely
fades over time. We hypothesized that women with a prior single-dose NVP exposure would have no more than a 10%
higher cumulative prevalence of failure of their NNRTI-containing antiretroviral therapy (ART) over the first 48 wk of therapy
than would women without a prior exposure.
Methods and Findings: We enrolled 355 NVP-exposed and 523 NVP-unexposed women at two sites in Zambia, one site in
Kenya, and two sites in Thailand into a prospective, non-inferiority cohort study and followed them for 48 wk on ART. Those
who died, discontinued NNRTI-containing ART, or had a plasma viral load $400 copies/ml at either the 24 wk or 48 wk
study visits and confirmed on repeat testing were characterized as having failed therapy. Overall, 114 of 355 NVP-exposed
women (32.1%) and 132 of 523 NVP-unexposed women (25.2%) met criteria for treatment failure. The difference in failure
rates between the exposure groups was 6.9% (95% confidence interval [CI] 0.8%–13.0%). The failure rates of women
stratified by our predefined exposure interval categories were as follows: 47 of 116 women in whom less than 6 mo elapsed
between exposure and starting ART failed therapy (40%; p,0.001 compared to unexposed women); 25 of 67 women in
whom 7–12 mo elapsed between exposure and starting ART failed therapy (37%; p = 0.04 compared to unexposed women);
and 42 of 172 women in whom more than 12 mo elapsed between exposure and starting ART failed therapy (24%; p = 0.82
compared to unexposed women). Locally weighted regression analysis also indicated a clear inverse relationship between
virologic failure and the exposure interval.
Conclusions: Prior exposure to single-dose NVP was associated with an increased risk of treatment failure; however, this risk
seems largely confined to women with a more recent exposure. Women requiring ART within 12 mo of NVP exposure
should not be prescribed an NNRTI-containing regimen as first-line therapy.
Please see later in the article for the Editors’ Summary.

Website

UoN Websites Search