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Objectives: Pregnancy results in physiological changes altering the pharmacokinetics of drugs metabolized by cytochrome P450 3A4 (CYP3A4). The urinary ratio of 6-β hydroxycortisol to cortisol (6βHF : F) is a marker of CYP3A4 induction. We sought to evaluate its change in antiretroviral (ARV)-treated HIV-1-infected women and to relate this change to ARV pharmacokinetics., Methods: Women receiving various ARVs had pharmacokinetic evaluations during the third trimester of pregnancy (>30 weeks) and postpartum with determination of 6βHF : F carried out on the same days. The Wilcoxon signed rank test was used to compare the ratio antepartum to postpartum. The relationship between the change in ratio and the change in pharmacokinetics was analysed using Kendall's tau., Results: 6βHF : F ratios were available for 107 women antepartum, with 54 having postpartum values. The ratio was higher antepartum (P=0.033) (median comparison 1.35; 95% confidence interval 1.01, 1.81). For 71 women taking a protease inhibitor (PI), the antepartum vs. postpartum 6βHF : F comparison was marginally significant (P=0.058). When the change in the 6βHF : F ratio was related to the change in the dose-adjusted ARV area under the plasma concentration vs. time curve (AUC) between antepartum and postpartum, the 35 subjects in the lopinavir/ritonavir (LPV/r) arms demonstrated an inverse relationship (P=0.125), albeit this correlation did not reach statistical significance., Conclusions: A 35% increase in the urinary 6βHF : F ratio was measured during late pregnancy compared with postpartum, indicating that CYP3A induction occurs during pregnancy. The trend towards an inverse relationship between the change in the 6βHF : F ratio and the change in the LPV AUC antepartum vs. postpartum suggests that CYP3A induction may be one mechanism behind altered LPV exposure during pregnancy., (© 2014 British HIV Association.)

Objectives: The aim of the study was to describe emtricitabine pharmacokinetics during pregnancy and postpartum., Methods: The International Maternal Pediatric and Adolescent AIDS Clinical Trials (IMPAACT), formerly Pediatric AIDS Clinical Trials Group (PACTG), study P1026s is a prospective pharmacokinetic study of HIV-infected pregnant women taking antiretrovirals for clinical indications, including a cohort taking emtricitabine 200 mg once daily. Intensive steady-state 24-hour emtricitabine pharmacokinetic profiles were performed during the third trimester and 6-12 weeks postpartum, and on maternal and umbilical cord blood samples collected at delivery. Emtricitabine was measured by liquid chromatography-mass spectrometry with a quantification limit of 0.0118 mg/L. The target emtricitabine area under the concentration versus time curve, from time 0 to 24 hours post dose (AUC(0-24) ), was ≥7 mg h/L (≤30% reduction from the typical AUC of 10 mg h/L in nonpregnant historical controls). Third-trimester and postpartum pharmacokinetics were compared within subjects., Results: Twenty-six women had pharmacokinetics assessed during the third trimester (median 35 weeks of gestation) and 22 postpartum (median 8 weeks postpartum). Mean [90% confidence interval (CI)] emtricitabine pharmacokinetic parameters during the third trimester vs. postpartum were, respectively: AUC: 8.0 (7.1-8.9) vs. 9.7 (8.6-10.9) mg h/L (P = 0.072); apparent clearance (CL/F): 25.0 (22.6-28.3) vs. 20.6 (18.4-23.2) L/h (P = 0.025); 24 hour post dose concentration (C(24) ): 0.058 (0.037-0.063) vs. 0.085 (0.070-0.010) mg/L (P = 0.006). The mean cord:maternal ratio was 1.2 (90% CI 1.0-1.5). The viral load was <400 HIV-1 RNA copies/mL in 24 of 26 women in the third trimester, in 24 of 26 at delivery, and in 15 of 19 postpartum. Within-subject comparisons demonstrated significantly higher CL/F and significantly lower C(24) during pregnancy; however, the C(24) was well above the inhibitory concentration 50%, or drug concentration that suppresses viral replication by half (IC(50) ) in all subjects., Conclusions: While we found higher emtricitabine CL/F and lower C(24) and AUC during pregnancy compared with postpartum, these changes were not sufficiently large to warrant dose adjustment during pregnancy. Umbilical cord blood concentrations were similar to maternal concentrations., (© 2011 British HIV Association.)

Objectives: Our objective was to evaluate the pharmacokinetics of nelfinavir (NFV) (625 mg tablets) 1250 mg twice daily during pregnancy and postpartum., Methods: The participants were HIV-1-infected pregnant women enrolled in P1026s and receiving NFV (625 mg tablets) 1250 mg twice daily as part of routine clinical care. Intensive steady-state 12-h NFV pharmacokinetic profiles were performed during pregnancy and postpartum. The target NFV area under the plasma concentration-time curve (AUC(0-12)) was >or=10th percentile NFV AUC(0-12) in non-pregnant historical controls (18.5 microg h/mL)., Results: Of 27 patients receiving NFV, pharmacokinetic data were available for four (second trimester), 27 (third trimester) and 22 (postpartum) patients. The NFV maximum concentration (C(max)), 12-h post-dose concentration (C(12)) and AUC(0-12) were significantly lower during the third trimester compared to postpartum (P

Objectives: To determine the impact of pregnancy on the pharmacokinetics (PK) of nevirapine (NVP) during chronic dosing in HIV-infected women and appropriate NVP dosing in this population., Methods: Twenty-six pregnant women participating in two open-label Pediatric AIDS Clinical Trials Group studies (P1022 and P1026S) were evaluated. Each patient received 200 mg NVP every 12 h and had PK evaluations during the second or third trimester; these evaluations were repeated postpartum. Paired maternal and cord blood NVP concentrations were collected at delivery in nine patients. Ante- and postpartum comparisons were made using paired t-tests and using a 'bioequivalence' approach to determine confidence interval (CI)., Results: The average NVP Area Under the Curve (AUC) was 56 +/- 13 mcg(*)h/mL antepartum and 61 +/- 15 mcg(*)h/mL postpartum. The typical parameters +/- standard error were apparent clearance (CL/F)=3.51 +/- 0.18 L/h and apparent volume of distribution (Vd/F)=121 +/- 19.8 L. There were no significant differences between antepartum and postpartum AUC or pre-dose concentrations. The AUC ratio was 0.90 with a 90% CI of the mean equal to 0.80-1.02. The median (+/- standard deviation) cord blood to maternal NVP concentration ratio was 0.91 +/- 0.90., Conclusions: Pregnancy does not alter NVP PK and the standard dose (200 mg every 12 h) is appropriate during pregnancy.

Background: Cesarean section before labor and before ruptured membranes ("elective cesarean section", or ECS) has been introduced as an intervention for the prevention of mother-to-child transmission (MTCT) of HIV-1. The role of mode of delivery in the management of HIV-1-infected women should be assessed in light of risks as well as benefits, since HIV-1-infected pregnant women must be provided with available information with which to make informed decisions regarding cesarean section and other options to prevent transmission of infection to their children., Objectives: Our objectives were to assess the efficacy (for prevention of MTCT of HIV-1) and the safety of ECS among HIV-1-infected women., Search Strategy: Electronic searches were undertaken using MEDLINE and other databases. Hand searches of reference lists of pertinent reviews and studies, as well as abstracts from relevant conferences, were also conducted. Experts in the field were contacted to locate any other studies. The search strategy was iterative., Selection Criteria: Randomized clinical trials assessing the efficacy and safety of ECS for prevention of MTCT of HIV-1 were included in the analysis, as were observational studies with relevant data., Data Collection and Analysis: Data regarding HIV-1 infection status of infants born to HIV-1-infected women according to mode of delivery were extracted from the reports of the studies. Similarly, data regarding postpartum morbidity (PPM) (including minor (e.g., febrile morbidity, urinary tract infection) and major (e.g., endometritis, thromboembolism) morbidity) of the HIV-1-infected women, and infant morbidity, according to mode of delivery were extracted., Main Results: One randomized clinical trial of the efficacy of ECS for prevention of MTCT of HIV-1 was identified. No data regarding infant morbidity according to the HIV-1-infected mother's mode of delivery were available. Data regarding PPM according to mode of delivery were available from this clinical trial as well as from five observational studies. Among HIV-1-infected women not taking antiretrovirals (ARVs) during pregnancy or taking only zidovudine, ECS was found to be efficacious for prevention of MTCT of HIV-1. PPM is generally higher among HIV-1-infected women who undergo cesarean as compared to vaginal delivery, with the risk with ECS being intermediate between that of vaginal delivery and NECS (including emergency procedures). Other factors associated with the risk of PPM among HIV-1-infected women include HIV-1 disease stage (more advanced disease, as manifested by lower CD4 counts and higher viral loads, being associated with a greater risk of PPM) and co-morbid conditions (e.g., diabetes)., Authors' Conclusions: ECS is an efficacious intervention for the prevention of MTCT among HIV-1-infected women not taking ARVs or taking only zidovudine. The risk of PPM with ECS is higher than that associated with vaginal delivery, yet lower than with NECS. Among HIV-1-infected women, more advanced maternal HIV-1 disease stage and concomitant medical conditions (e.g., diabetes) are independent risk factors for PPM. The risk of MTCT of HIV-1 according to mode of delivery among HIV-1-infected women with low viral loads (low either because the woman's HIV-1 disease is not advanced, or because her HIV-1 disease is well-controlled with ARVs) is unclear. Therefore, an important issue to be addressed in one or more large studies (individual studies or an individual patient data meta-analysis combining data from more than one study) is assessment of the effectiveness of ECS for prevention of MTCT of HIV-1 among HIV-1-infected women with undetectable viral loads (with or without receipt of highly active ARV therapy (HAART)).