Effect of Rifampin-Isoniazid-Containing Antituberculosis Therapy on Efavirenz Pharmacokinetics in HIV-Infected Children 3 to 14 Years Old.

We compared efavirenz pharmacokinetic (PK) parameters in children with tuberculosis (TB)/human immunodeficiency virus (HIV) coinfection on and off first-line antituberculosis therapy to that in HIV-infected children. Children 3 to 14 years old with HIV infection, with and without TB, were treated with standard efavirenz-based antiretroviral therapy without any efavirenz dose adjustments. The new World Health Organization-recommended antituberculosis drug dosages were used in the coinfected participants. Steady-state efavirenz concentrations after 4 weeks of antiretroviral therapy were measured using validated liquid chromatography with tandem mass spectrometry (LC-MS/MS) assays. Pharmacokinetic parameters were calculated using noncompartmental analysis. Between groups, PK parameters were compared by Wilcoxon rank-sum test and within group by signed-rank test. Of the 105 participants, 43 (41.0%) had TB coinfection. Children with TB/HIV coinfection compared to those with HIV infection were younger, had lower median weight-for-age Z score, and received a higher median efavirenz weight-adjusted dose. Geometric mean (GM) efavirenz peak concentration (Cmax), concentration at 12 h (C12h), Cmin, and total area under the curve from time 0 to 24 h (AUC0-24h) values were similar in children with HIV infection and those with TB/HIV coinfection during anti-TB therapy. Geometric mean efavirenz C12h, Cmin, and AUC0-24h values were lower in TB/HIV-coinfected patients off anti-TB therapy than in the children with HIV infection or TB/HIV coinfection on anti-TB therapy. Efavirenz clearance was lower and AUC0-24h was higher on than in patients off anti-TB therapy. Reduced efavirenz clearance by first-line anti-TB therapy at the population level led to similar PK parameters in HIV-infected children with and without TB coinfection. Our findings do not support modification of efavirenz weight-band dosing guidelines based on TB coinfection status in children. (The study was registered with ClinicalTrials.gov under registration number NCT01704144.).

Effect of First-Line Antituberculosis Therapy on Nevirapine Pharmacokinetics in Children Younger than Three Years Old.

Nevirapine-based antiretroviral therapy (ART) is one of the limited options in HIV-infected children younger than 3 years old (young children) with tuberculosis (TB) coinfection. To date, there are insufficient data to recommend nevirapine-based therapy during first-line antituberculosis (anti-TB) therapy in young children. We compared nevirapine pharmacokinetics (PK) in HIV-infected young children with and without TB coinfection. In the coinfected group, nevirapine PK was evaluated while on anti-TB therapy and after completing an anti-TB therapy regimen. Of 53 participants, 23 (43%) had TB-HIV coinfection. While the mean difference in nevirapine PK parameters between the two groups was not significant (P > 0.05), 14/23 (61%) of the children with TB-HIV coinfection and 9/30 (30%) with HIV infection had a nevirapine minimum concentration (Cmin) below the proposed target of 3.0 mg/liter (P = 0.03). In multivariate analysis, anti-TB therapy and the CYP2B6 516G>T genotype were joint predictors of nevirapine PK parameters. Differences in nevirapine PK parameters between the two groups were significant in children with CYP2B6 516GG but not the GT or TT genotype. Among 14 TB-HIV-coinfected participants with paired data, the geometric mean Cmin and area under the drug concentration-time curve from time zero to 12 h (AUC0-12) were about 34% lower when patients were taking anti-TB therapy, while the nevirapine apparent oral clearance (CL/F) was about 45% higher. While the induction effect of anti-TB therapy on nevirapine PK in our study was modest, the CYP2B6 genotype-dependent variability in the TB drug regimen effect would complicate any dose adjustment strategy in young children with TB-HIV coinfection. Alternate ART regimens that are more compatible with TB treatment in this age group are needed. (This study has been registered at ClinicalTrials.gov under identifier NCT01699633.).

Pharmacokinetics of the First-Line Antituberculosis Drugs in Ghanaian Children with Tuberculosis with or without HIV Coinfection.

Although human immunodeficiency virus (HIV) coinfection is the most important risk factor for a poor antituberculosis (anti-TB) treatment response, its effect on the pharmacokinetics of the first-line drugs in children is understudied. This study examined the pharmacokinetics of the four first-line anti-TB drugs in children with TB with and without HIV coinfection. Ghanaian children with TB on isoniazid, rifampin, pyrazinamide, and ethambutol for at least 4 weeks had blood samples collected predose and at 1, 2, 4, and 8 hours postdose. Drug concentrations were determined by validated liquid chromatography-mass spectrometry methods and pharmacokinetic parameters calculated using noncompartmental analysis. The area under the concentration-time curve from 0 to 8 h (AUC0-8), maximum concentration (Cmax), and apparent oral clearance divided by bioavailability (CL/F) for each drug were compared between children with and without HIV coinfection. Of 113 participants, 59 (52.2%) had HIV coinfection. The baseline characteristics were similar except that the coinfected patients were more likely to have lower weight-for-age and height-for-age Z scores (P < 0.05). Rifampin, pyrazinamide, and ethambutol median body weight-normalized CL/F values were significantly higher, whereas the plasma AUC0-8 values were lower, in the coinfected children than in those with TB alone. In the multivariate analysis, drug dose and HIV coinfection jointly influenced the apparent oral clearance and AUC0-8 for rifampin, pyrazinamide, and ethambutol. Isoniazid pharmacokinetics were not different by HIV coinfection status. HIV coinfection was associated with lower plasma exposure of three of the four first-line anti-TB drugs in children. Whether TB/HIV-coinfected children need higher dosages of rifampin, pyrazinamide, and ethambutol requires further investigation. (This study has been registered at ClinicalTrials.gov under identifier NCT01687504.).

Pharmacokinetics and pharmacodynamics of adult dolutegravir tablets in treatment-experienced children with HIV weighing at least 20 kg.

OBJECTIVE: Limited pharmacokinetic/pharmacodynamic data are a barrier to the scale-up of dolutegravir-based antiretroviral therapy (ART) in children. We examined the pharmacokinetics/pharmacodynamics of the adult film-coated dolutegravir 50 mg tablets in children with HIV infection weighing at least 20 kg. DESIGN: A prospective, observational, pharmacokinetic, and safety study. METHODS: Treatment-experienced children with HIV weighing at least 20 kg and evidence of viral load suppression on ART were enrolled and switched to dolutegravir-based therapy. After at least 4 weeks and 7 months on dolutegravir-based therapy, blood samples were collected at 0, 1, 4, 8, 12, and 24-h postdose. Dolutegravir concentrations were measured using validated LCMS/MS and pharmacokinetic parameters calculated by noncompartmental analysis. Descriptive statistics were used to summarize pharmacokinetic parameters and comparisons with published reference values. RESULTS: Of 25 participants, 92% were on efavirenz-based ART and 60.0% were men. Dolutegravir mean exposure, peak and trough concentrations at both pharmacokinetic visits were higher than the mean reference values in adults and children weighing 20 kg to less than 40 kg treated with 50 mg once daily, but were closer to the mean values in adults given 50 mg twice a day. Children weighing 20 kg to less than 40 kg had even higher dolutegravir exposures. The regimens were well tolerated with good virologic efficacy through week 48. CONCLUSION: The higher dolutegravir exposure in our study population suggests that further studies and close monitoring should investigate the adverse effects of dolutegravir in more children and in the long term.

The Impact of Different Parental Figures of Adolescents Living With HIV: An Evaluation of Family Structures, Perceived HIV Related Stigma, and Opportunities for Social Support.

Although antiretroviral therapy (ART) has changed the expected health outcomes for HIV, there are still issues related to stigma, how people living with HIV are perceived, and the availability of social support. The purpose of this study was to explore the associations between family structure and psychosocial wellbeing reflected by perceived HIV stigma and social support among adolescents living with HIV in Kumasi, Ghana. This article used baseline data from two mixed methods studies that evaluated the safety and preliminary efficacy of group-based support programs for ART adherence improvement among adolescents living in Kumasi, Ghana (N = 70, aged 12-18 years). A multivariate linear regression analysis was employed to examine the associations between family structure and the outcomes of stigma and social support. The main variables for family structure were single mothers and female caregivers. We found that single motherhood was a significant determinant of stigma. When compared to other categories of caregiver types, adolescents being raised by their single mothers was associated with a 0.259 decrease in the mean internal HIV stigma score (p = 0.029). Also, for female adolescents, being raised by a female guardian (e.g., mother, aunt, grandmother, and sister) was associated with a 20.92 point increase in the overall support index (p = 0.005). This study shows that the type of parent or guardian, and their gender, influences the perceived stigma and available social support among adolescents living with HIV in Ghana. Vulnerable subgroups of adolescents living with HIV, particularly those raised up by male caregivers, should be provided with additional support.

Group-based economic incentives to improve adherence to antiretroviral therapy among youth living with HIV: safety and preliminary efficacy from a pilot trial.

Poor adherence to antiretroviral therapy (ART) has significant consequences for adolescents. Conditional economic incentives (CEI) is an approach that may help address this challenge. This study evaluated the safety and preliminary efficacy of a group-based CEI program for ART adherence improvement among a sample of adolescents living in Ghana. A total of 35 adolescents (mean age: 14.7 years) on ART, though still with detectable viral load, were recruited from an HIV clinic and divided into 5 balanced groups to participate in peer-led group-based CEI activities during routine clinic visits. Four assessments were conducted across four visits at baseline and 3-, 6-, and 9-month follow-up, respectively. Main outcomes were ART adherence and viral load. Linear mixed models and thematic analysis were used for data analyses. The majority (91.4%) of the participants attended all four intervention activities. Participants reported missing an average of 1.06, 0.50, 0.91, 0.55 doses of ART in the past 7 days at baseline, 3-, 6-, and 9-month assessments, respectively. Most viral loads were ≥5,000 copies/ml at both baseline (68.6%) and 6-month assessments (54.3%). The incentive was divided between individual compensation for attending clinic and completing the assessment ($5 each, $20 in total) and a group-based compensation valued at $40 that was distributed during the 9-month assessment according to average group attendance (A≥90%, B≥75%, C≥60%, D<60%) and group-average viral load (A=undetectable, B=50-499, C=500-4999, D≥5,000). The mean earnings for the participants was $46.70 (77.8% of possible earning). Qualitative data suggested that the CEI helped ART adherence through gaining personal and group benefits. Participants reported no teasing, bullying, or other undesirable behaviors from group members. They liked getting money for attending clinics/group meetings and obtaining undetectable viral load. We concluded that a group-based CEI was safe and had the potential to improve ART adherence and reduce viral load among Ghanaian adolescents.

In-Clinic Adolescent Peer Group Support for Engagement in Sub-Saharan Africa: A Feasibility and Acceptability Trial.

Holding support groups with the same cohort of adolescents during clinic visits promises to increase engagement in care. Participants (N = 35 patients, aged 12-18, 50% female, from an adolescent HIV clinic in Kumasi, Ghana, were divided into 5 teams. Clinic visits were coordinated for members of each team. Team members participated in group discussions and activities while waiting to meet with their medical team. Teams met quarterly for 1 year. Participants reported benefits from talking with peers about the challenges of managing HIV. Clinic attendance improved from the preceding year (54% versus 84%). There were reductions in perceived internal stigma, perceived external stigma, worries about unintended disclosure from taking antiretroviral therapy (ART), and reduced ART concerns. The program demonstrated the feasibility, safety, and acceptability of facilitating increased interaction among adolescents living with HIV during clinic visits. Improvements in clinic attendance, perceived stigma, and concern about medications suggest that the intervention is a promising candidate for additional study.