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Objectives: To evaluate pharmacokinetics of nevirapine, lamivudine and stavudine in HIV-infected Zambian infants receiving fixed dose combination (FDC) antiretroviral tablets (Triomune Baby)., Design: Phase I/II study., Methods: Sixteen HIV-infected children at least 1 month, weighing 3 kg to less than 6 kg were enrolled. Blood was sampled at t = 0, 2, 6 and 12 h after observed intake of one FDC tablet (50 mg nevirapine, 6 mg stavudine, 30 mg lamivudine) 4 weeks after starting treatment. Safety and viral load response over 48 weeks were determined., Results: The median [interquartile range (IQR)] age, body weight and daily nevirapine dose in 15 included children (eight girls) were 4.8 (4.2, 8.4) months, 5.3 (4.3, 5.5) kg and 348 (326 385) mg/m, respectively. The median (IQR) nevirapine area under the concentration-time curve (AUC0-12 h), Cmax and C12 h were 70 (56, 104) h mg/l, 7.5 (6.2, 10) mg/l, and 4.3 (2.9, 6.9) mg/l, respectively. Values were on average higher than reported in adults, but approximately 20% lower than previously reported in children weighing at least 6 kg. Four of 15 (27%) children had a subtherapeutic nevirapine C12 h (defined as <3.0 mg/l) compared to only three of 63 (5%) children weighing at least 6 kg (P = 0.02), whereas children aged less than 5 months [three of six (50%)] may have the highest risk for subtherapeutic nevirapine C12 h (P = 0.24). No association was found between viral load values and nevirapine plasma pharmacokinetic parameters (P > 0.3). Stavudine-lamivudine pharmacokinetic parameters were broadly comparable to heavier children., Conclusion: Exposure to nevirapine in African, HIV-infected infants with low body weight taking FDC tablets appears on average to be adequate, but due to large intersubject variability a relatively high proportion had subtherapeutic nevirapine C12 h levels, particularly those aged less than 5 months.

Background: There are few medium-term virologic data in children from resource-limited settings taking adult fixed-dose-combination antiretroviral therapy (cART) without viral load monitoring., Methods: CHAP2 (Children with HIV Antibiotic Prophylaxis 2) is a prospective cohort of Zambian children using d4T/3TC/NVP adult Triomune30 dosed according to WHO guidelines., Results: A total of 103 children (19 with previous antiretroviral therapy) had follow-up >6 months. Median age at cART initiation was 8 years (IQR, 6-12) and CD4 8% (4-12). At 24 months, CD4% had increased by a median of 15% (7-25). For 74 children viral load was known/inferred: 51 of 74 (69%) had viral load <50 copies/mL (45 of 63 [71%] with no previous cART, 6 of 11 [55%] with previous cART; difference P = 0.30); 22 of 74 (30%) had viral load >1000 copies/mL. Of 26 children with resistance data, 25 (96%) had NNRTI resistance; 22 (84%) had M184V; 2 (8%) had Q151M; and 1 (4%) each had K65R, L74V, or K70E. Eight (31%) had > or =1 TAM. Those failing virologically with a genotypic sensitivity score of 0 for first-line therapy had a somewhat smaller increase in CD4% from baseline compared with those failing therapy with a genotypic sensitivity score >0 (+3 vs. +8, P = 0.13), and had somewhat lower CD4% at initiation of cART (2 vs. 11, P = 0.09). In 6 children with >1 resistance test, the estimated rate of accumulation of TAMs was 0.59/yr (95% confidence interval: 0.22-1.29)., Conclusions: Twenty-four month virologic responses to cART were good. However, the rate of TAM accumulation in those with rebound was higher than reported in Western adult cohorts, and there was some indication of a detrimental effect of high level resistance on CD4% change from baseline.

Full 12-hour pharmacokinetic profiles of nevirapine, stavudine, and lamivudine in HIV-infected children taking fixed-dose combination antiretroviral tablets have been reported previously by us. Further studies with these formulations could benefit from less-intensive pharmacokinetic sampling. Data from 65 African children were used to relate area under the plasma concentration versus time curve over 12 hours (AUC) to plasma concentrations of nevirapine, stavudine, or lamivudine at times t = 0, 1, 2, 4, 6, 8, and 12 hours after intake using linear regression. Limited sampling models were developed using leave-one-out crossvalidation. The predictive performance of each model was evaluated using the mean relative prediction error (mpe%) as an indicator of bias and the root mean squared relative prediction error (rmse%) as a measure of precision. A priori set criteria to accept a limited sampling model were: 95% confidence limit of the mpe% should include 0, rmse% less than 10%, a high correlation coefficient, and as few (convenient) samples as possible. Using only one sample did not lead to acceptable AUC predictions for stavudine or lamivudine, although the 6-hour sample was acceptable for nevirapine (mpe%: -0.8%, 95% confidence interval: -2.2 to +0.6); rmse%: 5.8%; r: 0.98). Using two samples, AUC predictions for stavudine and lamivudine improved considerably but did not meet the predefined acceptance criteria. Using three samples (1, 2, 6 hours), an accurate and precise limited sampling model for stavudine AUC (mpe%: -0.6%, 95% confidence interval: -2.2 to +1.0; rmse%: 6.5%; r: 0.98) and lamivudine AUC (mpe%: -0.3%, 95% confidence interval: -1.7 to +1.1; rmse%: 5.6%; r: 0.99) was found; this model was also highly accurate and precise for nevirapine AUC (mpe%: -0.2%, 95% confidence interval: -1.0 to +0.7; rmse%: 3.4%; r: 0.99). A limited sampling model using three time points (1, 2, 6 hours) can be used to predict nevirapine, stavudine, and lamivudine AUC accurately and precisely in HIV-infected African children.

Objective: Triomune Baby and Junior have been developed in response to the urgent need for appropriate paediatric fixed-dose combination antiretroviral tablets, with higher nevirapine to stavudine and lamivudine ratios than adult tablets, in accordance with paediatric recommendations. We determined whether this ratio results in optimal exposure in the target population., Methods: Seventy-one Zambian children were treated with Triomune Baby or Junior dosed according to weight bands. After 4 weeks or more, a 12-h pharmacokinetic curve was recorded. Antiretroviral plasma concentrations were assayed by high-performance liquid chromatography., Results: Six children were excluded because of poor adherence. Of the remaining 65, 24 (37%) were female, 24 (37%) weighed less than 15 kg and most were malnourished. Mean (range) nevirapine C12h, Cmax and AUC12h of 6.0 (1.4, 16.9) mg/l, 10.0 (3.8, 22.5) mg/l and 94.4 (32.1, 232) mg/l per hour were higher than those reported in adults. Nevirapine C12h was subtherapeutic (< 3.0 mg/l) in four children (6%). Mean stavudine and lamivudine C12h, Cmax, AUC12h (< 0.015 mg/l, 0.45 mg/l, 1.05 mg/l per hour and 0.09 mg/l, 1.33 mg/l, 5.42 mg/l per hour) were comparable to adults. There was no evidence of a difference in nevirapine AUC12h across weight bands (P = 0.2), whereas the difference in stavudine (P = 0.0003) and lamivudine AUC12h (P = 0.01) was driven by the single weight band with unequal dosing., Conclusion: Nevirapine concentrations were higher but more variable than in adults; the pharmacokinetic parameters of stavudine and lamivudine were comparable to adults. As nevirapine underdosing is of greater concern than overdosing, the Triomune Baby and Junior ratio appears to be appropriate for children weighing 6 kg and over. Further research is required for children under 6 kg.

Objective: To investigate nevirapine concentrations in African HIV-infected children receiving divided Triomune tablets (stavudine+lamivudine+nevirapine)., Design: Cross-sectional study., Methods: Steady-state plasma nevirapine concentrations were determined in Malawian and Zambian children aged 8 months to 18 years receiving Triomune in routine outpatient settings. Predictors from height-for-age, body mass index (BMI)-for-age, age, sex, post-dose sampling time and dose/m2/day were investigated using centre-stratified regression with backwards elimination (P<0.1)., Results: Of the 71 Malawian and 56 Zambian children (median age 8.4 vs 8.5 years, height-for-age -3.15 vs -1.84, respectively), only 1 (3%) of those prescribed > or =300 mg/m2/day nevirapine had subtherapeutic concentrations (<3 mg/l) compared with 22 (23%) of those prescribed <300 mg/m2/day; most children with subtherapeutic nevirapine concentrations were taking half or quarter Triomune tablets. Lower nevirapine concentrations were independently associated with lower height-for-age (indicating stunting) (0.37 mg/l per unit higher [95% confidence interval (CI): -0.003, +0.74]; P=0.05), lower prescribed dose/m2 (+0.89 mg/l per 50 mg/m2 higher [95% CI: 0.32, 1.46]; P=0.002) and higher BMI-for-age (indicating lack of wasting) (-0.42 mg/l per unit higher [95% CI: -0.80, -0.04]; P=0.03)., Conclusions: Currently available adult fixed-dose combination tablets are not well suited to children, particularly at younger ages: Triomune 30 is preferable to Triomune 40 because of the higher dose of nevirapine relative to stavudine. Further research is required to confirm that concentrations are reduced in stunted children but increased in wasted children. Development of appropriate paediatric fixed-dose combination tablets is essential if antiretroviral therapy is to be made widely available to children in resource-limited settings.

Background. Fixed-dose combination scored dispersible stavudine, lamivudine, and nevirapine minitablets (Triomune Baby and Junior; Cipla Ltd) are simpler and cheaper than liquid formulations and have correct dose ratios for human immunodeficiency virus-infected children. However, they cannot be used for dose escalation (DE) of nevirapine. Methods. Children were randomized to initiate antiretroviral therapy with full-dose (FD) nevirapine (Triomune Baby or Junior in the morning and evening) versus DE (half-dose nevirapine for 14 days [Triomune in themorning and stavudine-lamivudine {Lamivir-S} in the evening], then FD), in accordance with World Health Organization weight-band dosing tables. The primary end point was nevirapine-related clinical or laboratory grade 3 or 4 adverse events (AEs). Results. In total, 211 children (median [interquartile range {IQR}] age, 5 [2-9] years; median [IQR] CD4 cell percentage, 13% [8%-18%]) were enrolled and followed up for a median (IQR) of 92 (68-116) weeks. There were 31 grade 3 or 4 AEs that were definitely/probably or uncertainly related to nevirapine in the FD group (18.0 per 100 child-years), compared with 29 in the DE group (16.5 per 100 child-years) (incidence rate ratio, 1.09; 95% confidence interval, 0.63-1.87; P = .74). All were asymptomatic; 11 versus 3 were single grade 3 or 4 elevations in alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels, all of which resolved without a change in nevirapine dose or interruption. Thirteen (12%) FD versus 2 (2%) DE children had grade 1 (2 in FD) or grade 2 (11 in FD and 2 in DE) rashes. Three (2 in FD and 1 in DE) substituted efavirenz, 3 (FD) continued FD nevirapine, and 9 (8 in FD and 1 in DE) temporarily interrupted nevirapine, followed by successful DE. Predictors of nevirapine rash were older age (P = .003) and higher CD4 cell count for age (P = .03). Twentytwo children died (12 in FD and 10 in DE), 1 FD and 5 DE children at <4 weeks; none were considered to be drug related by independent review. Conclusions. Rash was more frequent with FD nevirapine, but 88% had no clinical toxicity; elevated AST or ALT levels were transient and resolved spontaneously, suggesting that routine laboratory monitoring has limited value. Dual pediatric stavudine-lamivudine minitablets are preferred for safe and simple DE; if unavailable, initiating FD Triomune requires timely review for rash, which could be managed by temporary reduction to half-dose Triomune or efavirenz substitution. [ABSTRACT FROM AUTHOR]

Purpose of the study To compare body circumferences, skin-fold thickness (SFT) and lipid levels (LL), as measures of lipodystrophy, among antiretroviral therapy (ART)-naïve and experienced children at enrolment into the CHAPAS-3 trial. Methods HIV-infected children in Uganda and Zambia, either ART-naïve or on stavudine (d4T) for ≥2 years without clinical lipodystrophy, were randomised to receive d4T, abacavir (ABC) or zidovudine (ZDV) with lamivudine and efavirenz (EFV) or nevirapine. At enrolment, mid-upper arm (MUAC) and calf (CC) circumferences, SFT (biceps, triceps, sub-scapular, supra-iliac) and fasting lipids (total cholesterol (TC), low density lipo-protein (LDL), high density lipoprotein (HDL), triglycerides (TRIG)) were measured. Age/sex adjusted z-scores of MUAC, CC, SFT and the sum of SFT (SSF) used Dutch reference data. ART-naïve and ART-experienced children were compared with t-tests using Stata v11.0. Summary of results Among 444 children, 224 (51%) were male and 331 (74.5%) ART-naïve. Mean (sd) CD4% was 19.7% (10.2) versus (vs) 34.2% (7.7) in ART-naïve vs ART-experienced children. The ART-naïve were younger than the ART-experienced children (median [IQR] age 2.5 [1.5, 4.0] vs 6.0 [5.5, 7.0] years, p<0.0001). Among the ART-experienced, 4/108 (3.7%) were on EFV and median (IQR) d4T use was 3.5 (2.7, 4.2) years. As expected, MUAC, CC, weight-for-age (WAZ) and height-for-age (HAZ) z-scores were lower in the ART-naïve; the ART-experienced had lower SFT z-scores and higher TC and HDL, but lower TRIG (Table 1). [ABSTRACT FROM AUTHOR]