Search

Objectives: The aim of this study was to determine whether oral zidovudine (ZDV) given during labour would provide a similar systemic exposure to the established intravenous regimen used to prevent mother-to-child transmission in HIV-infected pregnant women., Methods: ZDV pharmacokinetic parameters following oral administration during labour were determined in 10 HIV-infected pregnant women in active labour. All subjects were converted to intravenous ZDV prior to delivery., Results: In cohort 1 (n=6), subjects received 300 mg oral ZDV every 3 h for three doses. Oral therapy was well tolerated but plasma ZDV concentrations were substantially lower than previously reported with continuous intravenous therapy. Based on the pharmacokinetic results from cohort 1, women in cohort 2 (n=4) received an initial 600 mg dose followed by two 400 mg doses every 3 h. ZDV area under the curve and concentrations in cohort 2 increased approximately in proportion to the increase in dose but varied 6-7-fold. In both cohorts, ZDV pharmacokinetic parameters suggested erratic absorption., Conclusions: While ZDV exposure improved with the increased dosing regimen, our sample size was small and larger studies are needed to establish whether oral ZDV administration during labour can consistently provide equivalent exposure to intravenous administration.

Background: In 1999, we reported safety and efficacy data for short-course nevirapine from a Ugandan perinatal HIV-1 prevention trial when 496 babies were followed up to age 14-16 weeks. Safety and efficacy data are now presented for all babies followed up to 18 months of age., Methods: From November, 1997, to April, 1999, HIV-1 infected pregnant women in Kampala, Uganda, were randomly assigned nevirapine (200 mg at labour onset and 2mg/kg for babies within 72 h of birth; regimen A) or zidovudine (600 mg orally at labour onset and 300 mg every 3 h until delivery, and 4 mg/kg orally twice daily for babies for 7 days, regimenB). Infant HIV-1 testing was done at birth, age 6-8 and 14-16 weeks, and age 12 months by HIV-1 RNA PCR, and by HIV-1 antibody at 18 months. HIV-1 transmission and HIV-1-free survival were assessed using Kaplan-Meier analysis. We recorded adverse experiences through 6-8 weeks postpartum for mothers, and 18 months for babies. Efficacy analyses were by intention to treat., Findings: We enrolled 645 mothers to the study: 313 were assigned regimen A, 313 regimen B, and 19 placebo. Eight mothers were lost to follow-up before delivery. 99% of babies were breastfed (median duration 9 months). Estimated risks of HIV-1 transmission in the zidovudine and nevirapine groups were 10.3% and 8.1% at birth (p=0.35); 20.0% and 11.8% by age 6-8 weeks (p=0.0063); 22.1% and 13.5% by age 14-16 weeks (p=0.0064); and 25.8% and 15.7% by age 18 months (p=0.0023). Nevirapine was associated with a 41% (95% CI 16-59) reduction in relative risk of transmission through to age 18 months. Both regimens were well-tolerated with few serious side-effects., Interpretation: Intrapartum/neonatal nevirapine significantly lowered HIV-1 transmission risk in a breastfeeding population in Uganda compared with a short intrapartum/neonatal zidovudine regimen. The absolute 8.2% reduction in transmission at 6-8 weeks was sustained at age 18 months (10.1% [95% CI 3.5-16.6]). This simple, inexpensive, well-tolerated regimen has the potential to significantly decrease HIV-1 perinatal transmission in less-developed countries.

Objective: To determine zidovudine pharmacokinetics and tolerance in premature human human immunodeficiency virus-exposed infants., Study Design: Pediatric AIDS Clinical Trials Group Study 331 was a multicentered prospective, open-label study of the use of zidovudine in premature infants. Thirty-eight infants <35 weeks' gestational age (GA) were studied while receiving zidovudine 1.5 mg/kg every 12 hours until 2 weeks of age, then 2.0 mg/kg every 8 hours until 6 weeks of age. Population pharmacokinetics were evaluated at 1, 2, and 4 weeks' postnatal age; zidovudine doses were adjusted to maintain troughs <3 microM., Results: Zidovudine clearance was lower than reported in term infants at similar postnatal ages. Nine premature infants required dose reduction because of high levels (7/19 <30 weeks' and 2/19 >/=30 weeks' GA). Postnatal age, GA, serum creatinine, and furosemide use independently predicted zidovudine clearance. Zidovudine was generally well tolerated in this high-risk population., Conclusions: Zidovudine clearance is greatly reduced in premature infants. We recommend the following zidovudine dosing schedule in this population: 1.5 mg/kg (intravenous) or 2.0 mg/kg (oral) every 12 hours increased to every 8 hours at 2 weeks of age (>/=30 weeks' GA) or at 4 weeks (<30 weeks' GA).

Objective: To evaluate independent contributions of maternal factors to adverse pregnancy outcomes (APO) in HIV-infected women receiving antiretroviral therapy (ART)., Design: Risk 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., Methods: HIV 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., Results: Eighty-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., Conclusions: Risk 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.

Background: The AIDS Clinical Trials Group protocol 076 zidovudine prophylaxis regimen for HIV-1-infected pregnant women and their babies has been associated with a significant decrease in vertical HIV-1 transmission in non-breastfeeding women in developed countries. We compared the safety and efficacy of short-course nevirapine or zidovudine during labour and the first week of life., Methods: From November, 1997, to April, 1999, we enrolled 626 HIV-1-infected pregnant women at Mulago Hospital in Kampala, Uganda. We randomly assigned mothers nevirapine 200 mg orally at onset of labour and 2 mg/kg to babies within 72 h of birth, or zidovudine 600 mg orally to the mother at onset of labour and 300 mg every 3 h until delivery, and 4 mg/kg orally twice daily to babies for 7 days after birth. We tested babies for HIV-1 infection at birth, 6-8 weeks, and 14-16 weeks by HIV-1 RNA PCR. We assessed HIV-1 transmission and HIV-1-free survival with Kaplan-Meier analysis., Findings: Nearly all babies (98.8%) were breastfed, and 95.6% were still breastfeeding at age 14-16 weeks. The estimated risks of HIV-1 transmission in the zidovudine and nevirapine groups were: 10.4% and 8.2% at birth (p=0.354); 21.3% and 11.9% by age 6-8 weeks (p=0.0027); and 25.1% and 13.1% by age 14-16 weeks (p=0.0006). The efficacy of nevirapine compared with zidovudine was 47% (95% CI 20-64) up to age 14-16 weeks. The two regimens were well tolerated and adverse events were similar in the two groups., Interpretation: Nevirapine lowered the risk of HIV-1 transmission during the first 14-16 weeks of life by nearly 50% in a breastfeeding population. This simple and inexpensive regimen could decrease mother-to-child HIV-1 transmission in less-developed countries.

Zidovudine (ZDV) therapy during pregnancy and to the neonate reduced perinatal HIV transmission by nearly 70% in Pediatric AIDS Clinical Trials Group (PACTG) protocol 076. ZDV has been reported as positive in several in vitro carcinogenicity screening tests. We evaluated the short-term risk for tumors in 727 children with known ZDV exposure enrolled into the PACTG 076/219 and the Women and Infants Transmission Study (WITS). ZDV exposure in utero (antepartum) occurred in 97% and 99% of infants in PACTG 076/219 or WITS, respectively. Mean follow-up was 38.3 months with 366.9 person years follow-up for PACTG 076/219 and 14.5 months with 743.7 person years follow-up for WITS. No tumors of any nature were observed; relative risk was 0 (95% confidence interval [CI], 0-17.6). These data are reassuring regarding the short-term lack of tumors for ZDV-exposed infants observed to date. Longitudinal, standardized follow-up for infants with in utero antiretroviral exposure is necessary to assess long-term carcinogenicity.

Context: With the success of zidovudine chemoprophylaxis for prevention of perinatal transmission of the human immunodeficiency virus (HIV), an increasing number of HIV-exposed but uninfected children will have in utero exposure to zidovudine and other antiretroviral drugs., Objective: To evaluate the long-term effects of in utero exposure to zidovudine vs placebo among a randomized cohort of uninfected children., Design: Prospective cohort study based on data collected during Pediatric AIDS Clinical Trials Group Protocol 076, a perinatal zidovudine HIV prevention trial, and Protocol 219, a long-term observational protocol., Setting: Pediatric research clinics in the United States., Patients: Two hundred thirty-four uninfected children born to 230 HIV-infected women enrolled in Protocol 076 and followed up through February 28, 1997, in Protocol 219 (122 in the zidovudine group and 112 in the placebo group)., Main Outcome Measures: Physical growth measurements, immunologic parameters, cognitive/developmental function, occurrence of neoplasms, and mortality data assessed every 6 months for children younger than 24 months and yearly thereafter or as clinically indicated. Baseline echocardiogram and funduscopic evaluations were collected before 36 months of age., Results: Median age of children at time of last follow-up visit was 4.2 years (range, 3.2-5.6 years). There were no significant differences between children exposed to zidovudine and those who received placebo in terms of sequential data on lymphocyte subsets; weight, height, and head circumference z scores; and cognitive/developmental function. No deaths or malignancies occurred. Two children (both exposed to zidovudine) are being followed up for abnormal, unexplained ophthalmic findings. One child exposed to zidovudine had a mild cardiomyopathy on echocardiogram at the age of 48 months; the child is clinically asymptomatic., Conclusions: No adverse effects were observed in HIV-uninfected children with in utero and neonatal exposure to zidovudine followed up for as long as 5.6 years. Continued prospective evaluations of children born to HIV-infected women who are exposed to antiretroviral or immunotherapeutic agents are critical to assess the long-term safety of interventions that prevent perinatal HIV transmission.

Objective: The Pediatric AIDS Clinical Trials Group (PACTG) Protocol 300 assessed the clinical efficacy and safety of combination zidovudine/lamivudine (ZDV/3TC) compared with either didanosine (ddI) alone or combination ZDV/ddI., Study Design: Children with symptomatic human immunodeficiency virus (HIV) infection, 6 weeks through 15 years of age, were stratified according to age and randomly assigned to receive ddI, ZDV/3TC, or ZDV/ddI. The primary endpoint was time to first progression of HIV disease or death. Enrollment in the ZDV/ddI arm stopped after 11 months on the basis of results of PACTG Protocol 152, but blinded follow-up continued., Results: For the 471 children who could be evaluated, the median age was 2.7 years, median CD4 cell count was 699 cells/mm3, and median log10 HIV RNA was 5.1/mL. Median follow-up was 9.4 months. Patients receiving ZDV/3TC had a lower risk of HIV disease progression or death than those receiving ddI alone (15 vs 38 failures, P = .0006) and a lower risk of death (3 vs 15 deaths, P = .0039). Weight and height growth rates, CD4+ cell counts, and RNA concentrations showed results favoring ZDV/3TC. For patients concurrently randomized to all 3 treatment arms, both ZDV/3TC and ZDV/ddI recipients had lower risk of HIV disease progression than those who received ddI alone (P = .0026 and P = .0045)., Conclusions: Combination therapy with either ZDV/3TC or ZDV/ddI was superior, as determined by clinical and laboratory measures, to monotherapy with ddI.

The findings of a recent human immunodeficiency (HIV-1) prevention trial in the USA demonstrated that administration of an antiretroviral drug, zidovudine, to mothers during the prenatal and intrapartum periods, and to their neonates for 6 weeks, resulted in a two-thirds reduction in risk of perinatal transmission from 25.5% to 8.3%. These results were rapidly disseminated both in the USA and internationally. Since the release of these clinical trial results in the spring of 1994, several observational studies have documented a sharp increase in maternal and neonatal zidovudine use, as well as a significant decrease in perinatal HIV-1 transmission, with rates of about 8% being observed in non-clinical trial settings. Internationally, the results have led to the development of a variety of perinatal prevention trials that build on the success of the U.S. perinatal prevention trial but use modified strategies that can feasibly be carried out in developing countries.

A double-blind phase II trial compared zalcitabine (0.03 mg/kg/day) in combination with zidovudine (720 mg/m2/day) and zidovudine monotherapy in 250 clinically stable, previously zidovudine-treated, human immunodeficiency virus-infected children. The combination was well-tolerated except for an increased incidence of neutropenia (14%) compared with that in children receiving monotherapy (5%). No differences were noted for time to first AIDS-defining illness or death, neuropsychologic status, or weight Z scores. In patients in the combination arm, the CD4 cell count decline was slower (13% per year) than in patients receiving monotherapy (25% per year) (P = .03), and quantitative peripheral blood mononuclear cell virus load remained lower at all time points (P = .08). Deaths were fewer in patients receiving combination therapy (4) compared with those in patients receiving monotherapy (10) (P = .083). Thus, administration of zidovudine with zalcitabine to children with prior zidovudine treatment did not result in a significant increase in toxicity compared with that resulting from zidovudine monotherapy and demonstrated improvement in immunologic and virologic surrogate markers.