Nevirapine Plasma Concentrations are Still Detectable After More Than 2 Weeks in the Majority of Women Receiving Single-Dose Nevirapine
Single-dose nevirapine is a highly cost-effective strategy to reduce perinatal HIV-1 transmission. Its major disadvantage is the selection of nevirapine resistance in 20% to 30% of women, probably attributable to the long elimination half-life of nevirapine. To develop intervention strategies, it is important to know the interpatient variability in nevirapine half-life in women receiving a single dose of nevirapine. HIV-negative, healthy, nonpregnant Dutch women were eligible for this study. After administration of a single 200-mg dose of nevirapine to the subjects, blood was sampled for measurement of nevirapine twice a week for a total of 21 days. Nevirapine plasma levels were determined by a validated high-performance liquid chromatography method with a lower limit of quantification of 0.15 mg/L. The primary end point was the first sample with an undetectable nevirapine concentration. Forty-four subjects participated. The median age, height, and body weight (interquartile range) were 26 (21-33) years, 1.72 (1.68-1.75) m, and 64 (59-75) kg, respectively. The median elimination half-life of nevirapine was 56.7 hours, with a range of 25.6 to 164 hours. The time to the first undetectable nevirapine plasma concentration was 10 days in 4 subjects, 14 days in 12 subjects, 17 days in 12 subjects, and 21 days in 9 subjects. In the remaining 7 subjects, nevirapine was still detectable on day 21, the last day of sampling. Time to an undetectable nevirapine plasma concentration was influenced by oral contraceptive use but not by age, height, body weight, body surface area, alcohol use, or smoking. Most women who received a single 200-mg nevirapine dose still had detectable plasma concentrations of nevirapine after more than 2 weeks. This information is valuable for designing intervention studies to prevent the development of nevirapine resistance.
[Show abstract] [Hide abstract] ABSTRACT: Objective: Nevirapine is metabolized by cytochrome P450 (CYP) 2B6 and CYP3A4. We characterized relationships between clinical parameters, human genetics, pharmacokinetics, and human immunodeficiency virus type 1 (HIV-1) drug resistance mutations in pregnant women following single-dose intrapartum nevirapine. Methods: In AIDS Clinical Trials Group study A5207, women received nevirapine at onset of labor and were randomly assigned to receive lamivudine/zidovudine, emtricitabine/tenofovir, or lopinavir/ritonavir for 7 or 21 days. Plasma nevirapine level was quantified on postpartum day 1 and on weeks 1, 3, and 5. We assayed 214 polymorphisms in CYP2B6 and other genes and evaluated associations with pharmacokinetic parameters, including elimination constant, time to protein-adjusted 50% inhibitory concentration (IC50), and week 5 nevirapine level below the quantification limit. Results: Among 301 women with evaluable pharmacokinetic and genotype data, lower body mass index and random assignment to receive lopinavir/ritonavir were associated with more rapid nevirapine elimination. Among those of African ancestry, longer time to IC50 was associated with CYP2B6 983T → C (P = .004) but not with CYP2B6 516G → T (P = .8). Among Indians, slower nevirapine elimination was associated with CYP2B6 516G → T (P = .04). Emergent resistance was infrequent and not associated with pharmacokinetics or CYP2B6 genotype. Conclusions: The effects on plasma drug exposure following single-dose nevirapine may be greater for CYP2B6 983T → C than for 516G → T and are less pronounced than at steady state.0Comments 9Citations
- "cover the nevirapine " tail " decreases selection for drug-resistant HIV45678. The median plasma half-life of single-dose nevirapine (200 mg) ranges from approximately 45 to 75 hours, with considerable interindividual variability9101112. Nevirapine is metabolized primarily by cytochrome P450 (CYP) 2B6 and CYP3A4, with secondary metabolism by other CYPs131415. "
[Show abstract] [Hide abstract] ABSTRACT: Single-dose nevirapine (NVP) (sdNVP) can reduce the risk of HIV vertical transmission. We assessed risk factors for NVP resistance in plasma and breast milk from sdNVP-exposed Ugandan women. Samples were analyzed using the Roche AMPLICOR HIV-1 Monitor Test Kit, version 1.5, and the ViroSeq HIV-1 Genotyping System. NVP concentrations were determined by liquid chromatography with tandem mass spectroscopy. HIV genotypes (plasma and breast milk) were obtained for 30 women 4 weeks after sdNVP (HIV subtypes: 15A, 1C, 12D, two recombinant). NVP resistance was detected in 12 (40%) of 30 breast milk samples. There was a nonsignificant trend between detection of NVP resistance in breast milk and plasma (P = 0.06). There was no association of HIV resistance in breast milk with median maternal pre-NVP viral load or CD4 cell count, median breast milk viral load at 4 weeks, breast milk sodium more than 10 mmol/l, HIV subtype, or concentration of NVP in breast milk or plasma. NVP resistance was frequently detected in breast milk 4 weeks after sdNVP exposure. In this study, we were unable to identify specific factors associated with breast milk NVP resistance.0Comments 17Citations
- "decreased oral clearance) . NVP is transferred to breast milk after sdNVP exposure234 , and transmission of NVPresistant HIV to infants by breast-feeding has been documented [5,6]. In Zimbabwean women with subtype C HIV infection, NVP resistance was detected in breast milk from 13 (65%) of 20 women 8 weeks after sdNVP administration [7,8]; resistance test results could not be obtained for 12 other women, most of whom had undetectable breast milk HIV RNA. "
[Show abstract] [Hide abstract] ABSTRACT: Single-dose nevirapine (sdNVP)-which prevents mother-to-child transmission of HIV-selects non-nucleoside reverse-transcriptase inhibitor (NNRTI) resistance mutations in the majority of women and HIV-infected infants receiving it. This open-label, randomised trial examined the efficacy of short-course zidovudine (AZT) and lamivudine (3TC) with sdNVP in reducing NNRTI resistance in mothers, and as a secondary objective, in infants, in a setting where sdNVP was standard-of-care. sdNVP alone, administered at the onset of labour and to the infant, was compared to sdNVP with AZT plus 3TC, given as combivir (CBV) for 4 (NVP/CBV4) or 7 (NVP/CBV7) days, initiated simultaneously with sdNVP in labour; their newborns received the same regimens. Women were randomised 1ratio1ratio1. HIV-1 resistance was assessed by population sequencing at: baseline, 2, and 6 wk after birth. An unplanned interim analysis resulted in early stopping of the sdNVP arm. 406 pregnant women were randomised and took study medication (sdNVP 74, NVP/CBV4 164, and NVP/CBV7 168). HIV-1 resistance mutations emerged in 59.2%, 11.7%, and 7.3% of women in the sdNVP, NVP/CBV4, and NVP/CBV7 arms by 6 wk postpartum; differences between NVP-only and both NVP/CBV arms were significant (p<0.0001), but the difference between NVP/CBV4 and NVP/CBV7 was not (p = 0.27). Estimated efficacy comparing combined CBV arms with sdNVP was 85.6%. Similar resistance reductions were seen in infants who were HIV-infected by their 6-wk visit. A short course of AZT plus 3TC, supplementing maternal and infant sdNVP, reduces emergent NNRTI resistance mutations in both mothers and their infants. However, this trial was not powered to detect small differences between the CBV arms. www.ClinicalTrials.govNCT 00144183.0Comments 75Citations
- "Single-dose nevirapine (sdNVP) given to HIV-1 infected women in labour, followed by a single dose administered to their infants within 72 h of birth, is the simplest regimen to prevent intrapartum mother-to-child transmission (MTCT) of HIV-1 [1– 3] and is used extensively in resource-limited settings. However, NVP has a long half-life, leading to detectable plasma levels for as long as 3 wk following a single dose [4,5] and is associated with selection of non-nucleoside reverse-transcriptase inhibitor (NNRTI) resistance mutations detectable with population sequencing in 19%–75% of exposed mothers and 33%–87% of their infected infants678910. Selection of NNRTI-resistance mutations has also been described in 17%–45% of mothers who received sdNVP with a short course of antenatal zidovudine (AZT) [11,12]. "