Tuberculosis (TB) in children is a major global public health challenge. It is estimated that about 15 -20% of the global TB caseload occur in children < 15 years old. Children are also highly susceptible to the dual epidemics of human immunodeficiency virus (HIV) and TB. HIV-infected children are at a higher risk of developing active TB and TB-related death. The treatment of TB, as well as TB/HIV coinfection in children is complicated by poor drug absorption, drug-drug interactions, high pill burden and lack of appropriate formulations. In addition, dosage recommendations for children are often extrapolated from pharmacokinetic (PK) studies in adults. Consequently, the recommended dosages of the anti-TB and antiretroviral medications have been associated with a high frequency of sub-therapeutic plasma concentrations. The lack of pediatric PK data for commonly prescribed medications in children with TB and TB/HIV coinfection represents a major obstacle to the safe and effective treatment of these conditions in children. Our long-term goal is to develop a multidisciplinary research program to study the PK of available and new anti-TB and anti-HIV medications in children in sub-Saharan Africa. The objective of this proposal is to determine the PK of the first-line anti-TB and anti-HIV drugs, as well as characterize the factors associated with variable PK and drug-drug interactions in children in Ghana, West Africa. Our overarching hypothesis is that previous studies have underestimated the effect of developmental and genetic differences in drug metabolism, drug-drug interactions, as well as the risk for suboptimal drug concentrations in children. Our hypotheses will be pursued through three specific aims.
Aim 1 will determine whether the WHO recommended increased dosages of isoniazid, rifampin, pyrazinamide and ethambutol administered to African children with active TB infection (with or without HIV co- infection) achieve adult-equivalent therapeutic drug concentrations, and identify possible predictors of sub- therapeutic concentrations.
Aim 2 will determine whether rifampin-containing TB therapy induces drug clearance substantially in young TB/HIV co-infected children resulting in reduced nevirapine exposure as compared to children receiving nevirapine therapy without anti-TB therapy.
Aim 3 will determine whether rifampin-containing TB therapy significantly influence efavirenz concentrations in older TB/HIV co-infected children compared to HIV-infected children treated with a similar regimen in the absence of anti-TB treatment. Successful completion of the proposed studies will generate fundamental PK data for these commonly prescribed medications, as well as provide insights into predictors of the variable PK in children. Without such data, rational decisions about prescribing anti-TB and anti-HIV medications in children are not possible. PHS 398/2590 (Rev. 11/07) Page Continuation Format Page

Public Health Relevance

Globally, ~one million new cases of TB (with or with HIV coinfection) and ~130,000 TB deaths occur in children each year. The treatment of TB, and TB/HIV coinfection in children can reduce the high death rates, but it is complicated by poor drug absorption, drug-drug interactions, and lack of appropriate drug formulations. Currently, there is lack of adequate pharmacology data for commonly prescribed medications in children with TB and TB/HIV coinfection in sub-Saharan Africa, the most affected region. This situation represents a major obstacle to the safe and effective treatment of these conditions in children. Our long-term goal is to develop a multidisciplinary research program to study the pharmacology of available and new anti-TB and anti-HIV medications in children in West Africa. In the long-term, we hope that our research will provide urgently needed evidence to guide rational decisions about prescribing anti-TB and anti-HIV medications in children. PHS 398/2590 (Rev. 11/07) Page Continuation Format Page

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD071779-04
Application #
8845568
Study Section
AIDS Clinical Studies and Epidemiology Study Section (ACE)
Program Officer
Lorenzo, Eric
Project Start
2012-07-15
Project End
2016-04-30
Budget Start
2015-05-01
Budget End
2016-04-30
Support Year
4
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Miriam Hospital
Department
Type
DUNS #
063902704
City
Providence
State
RI
Country
United States
Zip Code
Horita, Yasuhiro; Alsultan, Abdullah; Kwara, Awewura et al. (2018) Evaluation of the Adequacy of WHO Revised Dosages of the First-Line Antituberculosis Drugs in Children with Tuberculosis Using Population Pharmacokinetic Modeling and Simulations. Antimicrob Agents Chemother 62:
Yang, Hongmei; Holden-Wiltse, Jeanne; Topham, David J et al. (2018) Maximum Likelihood Estimation of Titer via a Power Family of Four-Parameter Logistic Model. J Biopharm Stat 28:492-500
Yang, Hongmei; Enimil, Anthony; Gillani, Fizza S et al. (2018) Evaluation of the Adequacy of the 2010 Revised World Health Organization Recommended Dosages of the First-line Antituberculosis Drugs for Children: Adequacy of Revised Dosages of TB Drugs for Children. Pediatr Infect Dis J 37:43-51
Dompreh, Albert; Tang, Xiaoli; Zhou, Jianlin et al. (2018) Effect of Genetic Variation of NAT2 on Isoniazid and SLCO1B1 and CES2 on Rifampin Pharmacokinetics in Ghanaian Children with Tuberculosis. Antimicrob Agents Chemother 62:
Cao, Lei; Kwara, Awewura; Greenblatt, David J (2017) Metabolic interactions between acetaminophen (paracetamol) and two flavonoids, luteolin and quercetin, through in-vitro inhibition studies. J Pharm Pharmacol 69:1762-1772
Antwi, Sampson; Yang, Hongmei; Enimil, Anthony et al. (2017) Pharmacokinetics of the First-Line Antituberculosis Drugs in Ghanaian Children with Tuberculosis with or without HIV Coinfection. Antimicrob Agents Chemother 61:
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Yang, Hongmei; Baker, Steven F; González, Mario E et al. (2016) An improved method for estimating antibody titers in microneutralization assay using green fluorescent protein. J Biopharm Stat 26:409-20
Kwara, Awewura; Enimil, Anthony; Gillani, Fizza S et al. (2016) Pharmacokinetics of First-Line Antituberculosis Drugs Using WHO Revised Dosage in Children With Tuberculosis With and Without HIV Coinfection. J Pediatric Infect Dis Soc 5:356-365
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