To evaluate the pharmacokinetics and HIV viral load response following initiation during the third trimester of pregnancy of zidovudine plus standard-dose lopinavir boosted with ritonavir (LPV/r), ...twice daily, until delivery for the prevention of mother-to-child transmission of HIV.
Prospective study nested within a multicenter, three-arm, randomized, phase III prevention of mother-to-child transmission of HIV trial in Thailand (PHPT-5, ClinicalTrials.gov Identifier: NCT00409591).
Women randomized to receive 300 mg zidovudine and 400/100 mg LPV/r twice daily from 28 weeks' gestation, or as soon as possible thereafter, until delivery had intensive steady-state 12-h blood sampling performed. LPV/r pharmacokinetic parameters were calculated using noncompartmental analysis. Rules were defined a priori for a LPV/r dose escalation based on the proportion of women with an LPV area under the concentration-time curve (AUC) below 52 microg h/ml (10th percentile for LPV AUC in nonpregnant adults). HIV-1 RNA response was assessed during the third trimester.
Thirty-eight women were evaluable; at entry, median (range) gestational age was 29 (28-36) weeks, weight 59.5 (45.0-91.6) kg, CD4 cells count 442 (260-1327) cells/microl and HIV-1 RNA viral load 7818 (<40-402 015) copies/ml. Geometric mean (90% confidence interval) LPV AUC, Cmax and Cmin were 64.6 (59.7-69.8) microg h/ml, 8.1 (7.5-8.7) microg/ml and 2.7 (2.4-3.0) microg/ml, respectively. Thirty-one of 38 (81%) women had an LPV AUC above the AUC target. All women had a HIV-1 viral load less than 400 copies/ml at the time of delivery.
A short course of zidovudine plus standard-dose LPV/r initiated during the third trimester of pregnancy achieved adequate LPV exposure and virologic response.
Background. Intrapartum single-dose (SD) nevirapine (NVP) reduces perinatal transmission of human immunodeficiency virus (HIV) infection but selects for NVP-resistant virus, which compromises ...subsequent NVP-based therapy. A 1-week "tail" of lamivudine and zidovudine after SD-NVP decreases the risk of resistance. We hypothesized that increasing the duration or potency of the tail would further reduce this risk to < 10%, using a sensitive assay to measure resistance. Methods. HIV-infected pregnant Thai women with a CD4 cell count > 250 cells/μL, most receiving zidovudine, were randomized at 28-38 weeks gestation to receive 1 of 3 intrapartum and postpartum regimens: (A) zidovudine plus enteric-coated didanosine plus lopinavir and ritonavir for 7 days, (B) zidovudine plus enteric-coated didanosine for 30 days, or (C) regimen 1 for 30 days. The incidence of NVP resistance mutations at day 10 or week 6 post partum in each arm was compared with that of a historical comparison group who received prenatal zidovudine and SD-NVP. NVP resistance was identified by consensus sequencing and a sensitive oligonucleotide ligation assay (OLA). Results. At entry, the 169 participants had a median CD4 cell count of 456 cells/μL and an HIV load of 3.49log₁₀ copies/mL The incidence of mutations in each of the 3 P1032 arms was 0% by sequencing and 1.8%, 7.1%, and 5.3% by OLA in arms A, B, and C, respectively, compared with 13.4% by sequencing and 29.4% by OLA in the comparison group (P < .001 for each study arm vs comparison group). Grade 4 anemia developed in 1 woman. Conclusions. A 7-day tail of highly active combination therapy or 1 month of dual therapy after SD-NVP prevents most NVP resistance to minimal toxicity. Clinical Trials Registration. The IMPAACT P1032 Clinical Trial is NCT00109590, and the PHPT-2 Clinical Trial is NCT00398684.
Surveillance for mid- and long-term antiretroviral therapy (ART) toxicity in children is important for informing treatment guidelines. We assessed the safety of darunavir (DRV) and atazanavir (ATV), ...commonly used as second-line protease inhibitors following lopinavir/ritonavir, in Europe and Thailand.
Cohorts contributed individual patient data on adverse events (AE) in those aged <18 years taking DRV and ATV, respectively, to 02/2014. Rates of Division of AIDS (DAIDS) grade ≥3 laboratory AEs were calculated.
Of 431 patients on DRV and 372 on ATV, 317 (74%) and 301 (81%), respectively, had weight and dose data available, of whom 56 (18%) and 33 (9%) took the drugs at a non-approved age or dose. Median age at DRV and ATV start was 14.8 years (IQR 12.8-16.1) and 13.5 years (11.4-15.2); 43% and 26% had received ≥8 ART drugs previously. Overall rates of grade ≥3 AEs for absolute neutrophils, total cholesterol, triglycerides, pancreatic amylase, lipase and alanine aminotransferase (ALT) were ≤3/100 person-years (PY) on approved doses of both drugs, but 66/100 PY (95% CI 52, 84) for bilirubin after <12 months on ATV declining to 32/100 PY (95% CI 23, 44) after >24 months. Five serious drug-related clinical AEs were reported in four patients on ATV (one discontinued) and three in three patients on DRV (all discontinued), and did not substantially differ in those on approved compared to non-approved doses. Proportions on the drugs at last follow-up were 89% (383/431) for DRV and 81% (301/372) for ATV (including 73/92 with grade ≥3 hyperbilirubinaemia).
AEs were few in number and comparable for the two drugs, with the exception of high rates of hyperbilirubinaemia for ATV; few patients discontinued due to toxicity.
Fast ambiguity processing can be used in active time delay and Doppler identification in the sound fixing and ranging (SOFAR) propagation context. They need periodic signals generated from ...pseudo-random M sequences. In the particular case of the SOFAR, the range of the observed Doppler effect enables use of the fastest version, provided that the periodicity of the signal is correctly adjusted.
To determine nevirapine (NVP) plasma levels during the postpartum period after a single intrapartum NVP dose for the prevention of mother-to-child transmission.
Plasma samples at delivery and during ...days 8 to 45 postpartum were obtained from HIV-infected Thai women who received an intrapartum NVP dose in the Perinatal HIV Prevention Clinical Trial-2 (PHPT-2) for the prevention of perinatal HIV transmission. These data were combined with NVP concentration data from 2 phase 1 studies of NVP for a population analysis.
The median NVP level fell to 68 ng/mL (range: <50-228, n = 43) 8 to 14 days after dosing and to 51 ng/mL (range: <50-166, n = 25) between 15 and 21 days. During the second and third weeks postpartum, NVP levels were below the limit of quantitation in 23% and 44% of samples, respectively. Between 21 and 45 days, no sample had a quantifiable NVP concentration. A simulation derived from the population analysis predicts that NVP concentration falls to less than 10 ng/mL in 5% of women by 11 days, in 50% of women by 17.5 days, and in 95% of women by 28 days.
Significant NVP concentrations remained for up to 20 days in these Thai women. To ensure that coverage is maintained until NVP concentrations fall to nonsuppressive levels, 1 month of additional antiretroviral treatment after delivery should be considered to prevent the emergence of resistant viruses.
Background. The identification of risk factors for in utero and intrapartum transmission of human immunodeficiency virus type 1 (HIV-1) is crucial to the design and understanding of preventive ...interventions. Methods. The randomized Perinatal HIV Prevention Trial-1 enrolled 1437 pregnant women and their non-breast-fed infants, to compare the efficacy of various durations of zidovudine prophylaxis. Using univariate and multivariate logistic regression analyses, we studied the role that factors known or occurring at various times during gestation or delivery play in in utero and intrapartum transmission. Results. Variables independently associated with in utero transmission were HIV-1 load >35,000 copies/mL (adjusted odds ratio AOR, 4.2) and delayed initiation of maternal zidovudine prophylaxis until >31.4 weeks gestation (AOR, 3.0). Variables associated with intrapartum transmission were HIV-1 load >10,000 copies/mL (AOR, 3.8 for 10,000–35,000 copies/mL and 7.1 for >35,000 copies/mL), induction of labor (AOR, 2.6), and premature labor with tocolysis (AOR, 15.1). Conclusions. With the exception of very high HIV-1 load, risk factors for in utero transmission were different from those for intrapartum transmission. Optimal prophylactic interventions must address each of the major risk factors, with appropriate timing.
To assess hospitalization trends in HIV-infected children on antiretroviral therapy (ART) in Thailand, an important indicator of morbidity, ART effectiveness, and health service utilization.
...Prospective observational cohort
Children initiating ART in 1999-2009 were followed in 40 public hospitals. Hospitalization rate per 100 person-years were calculated from ART initiation to last follow-up/death. Costs to the healthcare provider were calculated using WHO inpatient estimates for Thailand. Zero-inflated Poisson models were used to examine risk factors for early (<12 months of ART) and late hospitalization (≥12 months) and frequency of admissions.
A total of 578 children initiated ART, median follow-up being 64 months interquartile range (IQR) 43-82; 211 (37%) children were hospitalized with 451 admissions. Hospitalization rates declined from 63 per 100 person-years at less than 6 months to approximately 10 per 100 person-years after 2 years of ART, and costs fell from $35 per patient-month to under $5, respectively. Age less than 2 years, US Centers of Disease Control and Prevention stage B/C, and stunting at ART initiation were associated with early hospitalization. Among those hospitalized, baseline CD4 cell percentage less than 5%, wasting, initiation on dual therapy, late calendar year, and female sex were associated with higher incidence of early admissions (P <0.02). There were no predictors of late hospitalization, although previous hospitalization in less than 12 months of ART was associated with three times higher incidence of late admissions (P < 0.0001).
One in three children required hospitalization after ART. Admissions were highest in the first year of therapy and rapidly declined thereafter. Young age, advanced disease stage, and stunting at baseline were predictive of early hospitalization. Treatment initiation before disease progression would likely reduce hospitalization and alleviate demands on healthcare services.
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