Alice Stek

Reduced lopinavir exposure during pregnancy.

Background:Optimal antiretroviral exposure during pregnancy is critical for prevention of mother-to-child HIV transmission and for maternal health. Pregnancy can alter antiretroviral pharmacokinetics. Our objective was to describe lopinavir/ritonavir (LPV/r) pharmacokinetics during pregnancy. Methods:We performed intensive steady-state 12-h pharmacokinetic profiles of lopinavir and ritonavir (three capsules: LPV 400 mg/r 100 mg) at 30–36 weeks gestation and 6–12 weeks postpartum. Maternal and umbilical cord blood samples were obtained at delivery. We measured LPV and ritonavir by reverse-phase high-performance liquid chromatography. Target LPV area under concentration versus time curve (AUC) was ≥ 52 μg h/ml, the estimated 10th percentile LPV AUC in non-pregnant historical controls (mean AUC = 83 μg h/ml). Results:Seventeen women completed antepartum evaluations; average gestational age was 35 weeks. Geometric mean antepartum LPV AUC was 44.4 μg h/ml [90% confidence interval (CI), 38.7–50.9] and 12-h post-dose concentration (C12h) was 1.6 μg/ml (90% CI, 1.1–2.5). Twelve women completed postpartum evaluations; geometric mean LPV AUC was 65.2 μg h/ml (90% CI, 49.7–85.4) and C12h was 4.6 μg/ml (90% CI, 3.7–5.7). The geometric mean ratio of antepartum/postpartum LPV AUC was 0.72 (90% CI, 0.54–0.96). Fourteen of 17 (82%) pregnant and three of 12 (25%) postpartum women did not meet our target LPV AUC. The ratio of cord blood/maternal LPV concentration in ten paired detectable samples was 0.2 ± 0.13. Conclusions:LPV/r exposure during late pregnancy was lower compared to postpartum and compared to non-pregnant historical controls. Small amounts of lopinavir cross the placenta. The pharmacokinetics, safety, and effectiveness of increased LPV/r dosing during the third trimester of pregnancy should be investigated.

Efficacy of Zidovudine and Human Immunodeficiency Virus (HIV) Hyperimmune Immunoglobulin for Reducing Perinatal HIV Transmission from HIV-Infected Women with Advanced Disease: Results of Pediatric AIDS Clinical Trials Group Protocol 185

Pediatric AIDS Clinical Trials Group protocol 185 evaluated whether zidovudine combined with human immunodeficiency virus (HIV) hyperimmune immunoglobulin (HIVIG) infusions administered monthly during pregnancy and to the neonate at birth would significantly lower perinatal HIV transmission compared with treatment with zidovudine and intravenous immunoglobulin (IVIG) without HIV antibody. Subjects had baseline CD4 cell counts </=500/microL (22% had counts <200/microL) and required zidovudine for maternal health (24% received zidovudine before pregnancy). Transmission was associated with lower maternal baseline CD4 cell count (odds ratio, 1.58 per 100-cell decrement; P=.005; 10.0% vs. 3.6% transmission for count <200 vs. >/=200/microL) but not with time of zidovudine initiation (5.6% vs. 4.8% if started before vs. during pregnancy; P=. 75). The Kaplan-Meier transmission rate for HIVIG recipients was 4. 1% (95% confidence interval, 1.5%-6.7%) and for IVIG recipients was 6.0% (2.8%-9.1%) (P=.36). The unexpectedly low transmission confirmed that zidovudine prophylaxis is highly effective, even for women with advanced HIV disease and prior zidovudine therapy, although it limited the studys ability to address whether passive immunization diminishes perinatal transmission.

Pregnancy rates and predictors of conception, miscarriage and abortion in US women with HIV.

Objective: To determine frequency and outcomes of pregnancy in US women with HIV before and after introduction of highly active antiretroviral therapy (HAART). Design: Prospective cohort study at six US centers. Methods: HIV seropositive and at-risk seronegative women reported pregnancy outcomes at 6-month intervals during the period 1 October 1994 to 31 March 2002. Outcomes were tabulated and pregnancy rates calculated. Logistic regression defined outcome correlates. Results: Pregnancy rates were 7.4 and 15.2 per 100 person-years in seropositive and seronegative women, respectively (P < 0.0001). Among seropositives, 119 (36%) pregnancies ended in live birth, six (2%) in stillbirth, 126 (36%) in abortion, 83 (24%) in miscarriage, 16 (5%) in ectopic pregnancy, and two (1%) in other outcomes (P = nonsignificant versus seronegatives). Independent baseline correlates of conception in seropositives included younger age [odds ratio (OR), 1.20; 95% confidence interval (CI), 1.16–1.23], prior abortion (OR, 1.79; 95% CI, 1.25–2.63), lower HIV RNA levels (OR, 1.30; 95% CI, 1.10–1.54 for each log decrease), and being unmarried (OR, 1.59; 95% CI, 1.02–2.44). Baseline antiretroviral use at baseline was linked to lower conception risk (OR, 0.34; 95% CI, 0.49–0.98 for mono- or combination therapy; OR, 0.34; 95% CI, 0.03–4.28 for HAART). Abortion was less likely during the HAART era, (OR, 0.68; 95% CI, 0.35–1.33 during the early HAART era; OR, 0.46; 95% CI, 0.23–0.90 during the later HAART era, compared with before HAART). Conclusions: Women with HIV were less likely to conceive than at-risk uninfected women, but pregnancy outcomes were similar. Abortion became less common after the introduction of HAART.

Prenatal Protease Inhibitor Use and Risk of Preterm Birth among HIV-Infected Women Initiating Antiretroviral Drugs during Pregnancy

BACKGROUND Conflicting results have been reported among studies of protease inhibitor (PI) use during pregnancy and preterm birth. Uncontrolled confounding by indication may explain some of the differences among studies. METHODS In total, 777 human immunodeficiency virus (HIV)-infected pregnant women in a prospective cohort who were not receiving antiretroviral (ARV) treatment at conception were studied. Births <37 weeks gestation were reviewed, and deliveries due to spontaneous labor and/or rupture of membranes were identified. Risk of preterm birth and low birth weight (<2500 g) were evaluated by using multivariable logistic regression. RESULTS Of the study population, 558 (72%) received combination ARV with PI during pregnancy, and a total of 130 preterm births were observed. In adjusted analyses, combination ARV with PI was not significantly associated with spontaneous preterm birth, compared to ARV without PI (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.70-2.12). Sensitivity analyses that included women who received ARV prior to pregnancy also did not identify a significant association (OR, 1.34; 95% CI, 0.84-2.16). Low birth weight results were similar. CONCLUSIONS No evidence of an association between use of combination ARV with PI during pregnancy and preterm birth was found. Our study supports current guidelines that promote consideration of combination ARV for all HIV-infected pregnant women.

Adherence to Antiretrovirals Among US Women During and After Pregnancy

Background:Antiretrovirals (ARVs) are recommended for maternal health and to reduce HIV-1 mother-to-child transmission, but suboptimal adherence can counteract its benefits. Objectives:To describe antepartum and postpartum adherence to ARV regimens and factors associated with adherence. Methods:We assessed adherence rates among subjects enrolled in Pediatric AIDS Clinical Trials Group Protocol 1025 from August 2002 to July 2005 on tablet formulations with at least one self-report adherence assessment. Perfectly adherent subjects reported no missed doses 4 days before their study visit. Generalized estimating equations were used to compare antepartum with postpartum adherence rates and to identify factors associated with perfect adherence. Results:Of 519 eligible subjects, 334/445 (75%) reported perfect adherence during pregnancy. This rate significantly decreased 6, 24, and 48 weeks postpartum [185/284 (65%), 76/118 (64%), and 42/64 (66%), respectively (P < 0.01)]. Pregnant subjects with perfect adherence had lower viral loads. The odds of perfect adherence were significantly higher for women who initiated ARVs during pregnancy (P < 0.01), did not have AIDS (P = 0.02), never missed prenatal vitamins (P < 0.01), never used marijuana (P = 0.05), or felt happy all or most of the time (P < 0.01). Conclusions:Perfect adherence to ARVs was better antepartum, but overall rates were low. Interventions to improve adherence during pregnancy are needed.

Pharmacokinetics of Saquinavir plus Low-Dose Ritonavir in Human Immunodeficiency Virus-Infected Pregnant Women

ABSTRACT The physiologic changes that occur during pregnancy make it difficult to predict antiretroviral pharmacokinetics (PKs), but few data exist on the PKs of protease inhibitors in human immunodeficiency virus (HIV)-infected pregnant women. The objective of the present study was to determine the PKs of ritonavir (RTV)-enhanced saquinavir (SQV) in HIV-infected pregnant women by an area under the curve (AUC)-targeted approach. A phase I, formal PK evaluation was conducted with HIV-infected pregnant woman during gestation, during labor and delivery, and at 6 weeks postpartum. The SQV-RTV regimen was 800/100 mg twice a day (b.i.d.), and nucleoside analogs were administered concomitantly. The SQV exposure targeted was an AUC at 24 h of 10,000 ng · h/ml. Participants were evaluated for 12-h steady-state PKs at each time period. Thirteen subjects completed the PK evaluations during gestation, 7 completed the PK evaluations at labor and delivery, and 12 completed the PK evaluations postpartum. The mean baseline weight was 67.4 kg, and the median length of gestation was 23.3 weeks. All subjects achieved SQV exposures in excess of the target AUC. The SQV AUCs at 12 h (AUC12s) during gestation (29,373 ± 17,524 ng · h/ml [mean ± standard deviation]), during labor and delivery (26,189 ± 22,138 ng · h/ml), and during the postpartum period (35,376 ± 26,379 ng · h/ml) were not significantly different. The mean values of the PK parameters for RTV were lower during gestation than during the postpartum period: for AUC12, 7,811 and 13,127 ng · h/ml, respectively; for trough concentrations, 376 and 632 ng/ml, respectively; and for maximum concentrations, 1,256 and 2,252 ng/ml, respectively (P ≤ 0.05 for all comparisons). This is the first formal PK evaluation of a dual protease inhibitor regimen with HIV-infected pregnant women. The level of SQV exposure was sufficient at each time of evaluation. These data demonstrate large variability in SQV and RTV concentrations and suggest that RTV concentrations are altered by pregnancy. These PK results suggest that SQV-RTV at 800/100 mg b.i.d. appears to be a reasonable treatment option for this population.

Risk factors for preterm birth, low birth weight, and intrauterine growth retardation in infants born to HIV-infected pregnant women receiving zidovudine

ObjectiveTo evaluate independent contributions of maternal factors to adverse pregnancy outcomes (APO) in HIV-infected women receiving antiretroviral therapy (ART). DesignRisk factors for preterm birth (< 37 weeks gestation), low birth weight (LBW) (< 2500 g), and intrauterine growth retardation (IUGR) (birth weight < 10th percentile for gestational age) examined in 497 HIV-infected pregnant women enrolled in PACTG 185, a perinatal clinical trial. MethodsHIV RNA copy number, culture titer, and CD4 lymphocyte counts were measured during pregnancy. Information collected included antenatal use of cigarettes, alcohol, illicit drugs; ART; obstetric history and complications. ResultsEighty-six percent were minority race/ethnicity; 86% received antenatal monotherapy, predominantly zidovudine (ZDV), and 14% received combination antiretrovirals. Preterm birth occurred in 17%, LBW in 13%, IUGR in 6%. Risk of preterm birth was independently associated with prior preterm birth [odds ratio (OR) 3.34;P  < 0.001], multiple gestation (OR, 6.02;P  = 0.011), antenatal alcohol use (OR, 1.91;P  = 0.038), and antenatal diagnosis of genital herpes (OR, 0.24;P  = 0.022) or pre-eclampsia (OR, 6.36;P  = 0.025). LBW was associated with antenatal diagnosis of genital herpes (OR, 0.08;P  = 0.014) and pre-eclampsia (OR, 5.25;P  = 0.049), and baseline HIV culture titer (OR, 1.41;P  = 0.037). IUGR was associated with multiple gestation (OR, 8.20;P  = 0.010), antenatal cigarette use (OR, 3.60;P  = 0.008), and pre-eclampsia (OR, 12.90;P  = 0.007). Maternal immune status and HIV RNA copy number were not associated with APO. ConclusionsRisk factors for APO in antiretroviral treated HIV-infected women are similar to those reported for uninfected women. These data suggest that provision of prenatal care and ART may reduce APO.

Lopinavir tablet pharmacokinetics with an increased dose during pregnancy.

Objective:Reduced lopinavir concentrations have been demonstrated with use of the capsule formulation during the third trimester of pregnancy. This study determined lopinavir exposure with an increased dose of the new tablet formulation during the third trimester. Design:International Maternal Pediatric Adolescent AIDS Clinical Trials 1026s is a prospective nonblinded pharmacokinetic study in HIV-infected pregnant women, including a cohort receiving 2 lopinavir/ritonavir tablets (400 mg/100 mg) twice daily during the second trimester, 3 tablets (600 mg/150 mg) twice daily during the third trimester, and 2 tablets (400 mg/100 mg) twice daily postdelivery through 2 weeks postpartum. Methods:Steady-state 12-hour pharmacokinetic profiles were performed during pregnancy and at 2 weeks postpartum. Lopinavir and ritonavir were measured by reverse-phase high-performance liquid chromatography (detection limit, 0.09 mcg/mL). Results:Thirty-three women were studied. Median lopinavir AUC for the second trimester (n = 11), third trimester (n = 33), and postpartum (n = 27) were 72, 96, and 133 mcg·hr/mL, respectively. Median minimum lopinavir concentrations were 3.4, 4.9, and 6.9 mcg/mL. Conclusions:The higher lopinavir/ritonavir tablet dose (600 mg/150 mg) provided exposure during the third trimester similar to the average AUC (98 mcg·hr·mL−1) in nonpregnant adults taking 400 mg/100 mg twice daily. The higher dose should be used during the second and third trimesters of pregnancy. Postpartum dosing can be reduced to standard dosing before 2 weeks postpartum.

Atazanavir Pharmacokinetics With and Without Tenofovir during Pregnancy

Background:Few data are available describing atazanavir exposure during pregnancy, especially when used in combination with tenofovir, whose coadministration with atazanavir results in decreased atazanavir exposure. Design:International Maternal Pediatric Adolescent AIDS Clinical Trials 1026s is an ongoing, prospective, nonblinded study of antiretroviral pharmacokinetics in HIV-infected pregnant women that included 2 cohorts receiving atazanavir/ritonavir 300 mg/100 mg once daily, either with or without tenofovir. Methods:Intensive steady-state 24-hour pharmacokinetic profiles were performed during the third trimester and at 6-12 weeks postpartum. Atazanavir was measured by reverse-phase high-performance liquid chromatography (detection limit 0.047 mcg/mL). Pharmacokinetic targets were the estimated 10th percentile atazanavir area under the concentration versus time curve [(AUC): 29.4 mcg·hr·mL−1] in nonpregnant historical controls (mean AUC = 57 mcg·hr·mL−1) and a trough concentration of 0.15 mcg/mL, the concentration target used in therapeutic drug monitoring programs. Results:Median atazanavir AUC was reduced during the third trimester compared with postpartum for subjects not receiving tenofovir (41.9 vs. 57.9 mcg·hr·mL−1, P = 0.02) and for subjects receiving tenofovir (28.8 vs. 39.6 mcg·hr·mL−1, P = 0.04). During the third trimester, AUC was below the target in 33% (6 of 18) of women not receiving tenofovir and 55% (11 of 20) of women receiving tenofovir. Trough concentration was below the target in 6% (1 of 18) of women not receiving tenofovir and 15% (3 of 20) of women receiving tenofovir. The median (range) ratio of cord blood/maternal atazanavir concentration in 29-paired samples was 0.18 (0-0.45). Conclusions:Atazanavir exposure is reduced by pregnancy and by concomitant tenofovir use. A dose increase of atazanavir/ritonavir to 400 mg/100 mg may be necessary in pregnant women to ensure atazanavir exposure equivalent to that seen in nonpregnant adults.

Depo-medroxyprogesterone in women on antiretroviral therapy: effective contraception and lack of clinically significant interactions.

We conducted an open‐label, steady‐state pharmacokinetic (PK) study of drug interactions among HIV‐infected women treated with depo‐medroxyprogesterone acetate (DMPA) while on nucleoside analogues plus nelfinavir (N=21), efavirenz (N=17), or nevirapine (N=16); or nucleosides only or no antiretroviral therapy as a control group (N=16). PK parameters were estimated using non‐compartmental analysis, with between‐group comparisons of medroxyprogesterone acetate (MPA) PKs and within‐subject comparisons of ARV PKs before and 4 weeks after DMPA dosing. Plasma progesterone levels were measured at baseline and at 2, 4, 6, 8, 10, and 12 weeks after DMPA dosing. There were no significant changes in MPA area under the concentration curve, peak or trough concentrations, or apparent clearance in the nelfinavir, efavirenz, or nevirapine groups compared to the control group. Minor changes in nelfinavir and nevirapine drug exposure were seen after DMPA, but were not considered clinically significant. Suppression of ovulation was maintained.