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Tam J, Lau E, Read S, Bitnun A. Is Routine Therapeutic Drug Monitoring of Anti-Retroviral Agents Warranted in Children Living with HIV? J Pediatr Pharmacol Ther 2022; 27:551-557. [DOI: 10.5863/1551-6776-27.6.551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 11/29/2021] [Indexed: 11/11/2022]
Abstract
OBJECTIVE
The utility of routine therapeutic drug monitoring (TDM) in children living with HIV has not been extensively studied. The purpose of this study was to assess this strategy.
METHODS
This was a single-center, prospective observational study of routine TDM for protease inhibitors (PIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and integrase strand transfer inhibitors (INSTIs) in children living with HIV who were receiving antiretroviral therapy (ART) between February and December 2014. Outcome measures included the proportion of serum antiretroviral (ARV) medication concentrations in the therapeutic range (target values extrapolated from adult data) and the effect of serum concentrations on virologic control, medication adherence, and toxicity.
RESULTS
Forty-eight children with a median age of 13 years (interquartile range, 3–18) were included. Median viral load (VL) and CD4% were <40 copies/mL (range, <40–124) and 37.4% (range, 8.4–47.9), respectively. Adherence was considered excellent in 95.8% of patients. Of the 50 serum trough concentrations (PI n = 19 [38%]; NNRTI n = 27 [54%]; INSTI n = 4 [8%]), 66% (n = 33) were in the therapeutic range, 12% (n = 6) were subtherapeutic, and 22% (n = 11) were supratherapeutic. There was no statistically significant correlation between serum ARV concentrations and patient demographics, VL, CD4%, or adherence. No clinically significant adverse events were noted. One dose adjustment was made for a subtherapeutic serum raltegravir concentration, likely attributable to interaction with ritonavir.
CONCLUSIONS
This study does not support routine TDM in healthy children living with HIV who are well controlled on antiretroviral medication regimens. A more targeted strategy, such as when adherence is questioned or when there are suspected drug interactions, may be more appropriate.
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Affiliation(s)
- Jennifer Tam
- Division of Infectious Diseases, Department of Pediatrics (JT, SR, AB), The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto (JT, EL, SR, AB), Toronto, ON, Canada
- Division of Infectious Diseases, Department of Pediatrics (JT), BC Children's Hospital, Vancouver, BC, Canada
| | - Elaine Lau
- University of Toronto (JT, EL, SR, AB), Toronto, ON, Canada
- Department of Pharmacy (EL), The Hospital for Sick Children, Toronto, ON, Canada
| | - Stanley Read
- Division of Infectious Diseases, Department of Pediatrics (JT, SR, AB), The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto (JT, EL, SR, AB), Toronto, ON, Canada
| | - Ari Bitnun
- Division of Infectious Diseases, Department of Pediatrics (JT, SR, AB), The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto (JT, EL, SR, AB), Toronto, ON, Canada
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Pressiat C, Toni TD, Treluyer JM, Yonaba C, Dahourou DL, Malateste K, Seguin-Devaux C, Leroy V, Hirt D. High nevirapine levels in breast milk and consequences in HIV-infected child when initiated on antiretroviral therapy. AIDS 2021; 35:2409-2410. [PMID: 34723858 DOI: 10.1097/qad.0000000000003043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Claire Pressiat
- Pharmacology Department, AP-HP, Hôpitaux Universitaires Henri Mondor, Paris Est-Créteil University, Créteil
| | - Thomas d'Aquin Toni
- Centre de Diagnostic et de Recherche sur le Sida (CeDReS), Centre Hospitalier Universitaire Treichville, Abidjan, Côte d'Ivoire
| | - Jean-Marc Treluyer
- Paris Descartes University, EA 7323
- Clinical Pharmacology Department, AP-HP, Paris Centre Hospital Group, Paris
| | - Caroline Yonaba
- Pediatric Department, Centre Hospitalier Universitaire Yalgado Ouédraogo, Ouagadougou, Burkina Faso
| | - Désiré Lucien Dahourou
- MONOD Project, ANRS 12206, Centre de Recherche Internationale pour la Santé, Ouagadougou
- Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Institut de Recherche en Sciences de la Santé (IRSS), Ouagadougou
- University of Bordeaux, Inserm, Institut de Recherche pour le Développement (IRD), UMR 1219, Bordeaux
| | - Karen Malateste
- University of Bordeaux, Inserm, Institut de Recherche pour le Développement (IRD), UMR 1219, Bordeaux
| | | | - Valériane Leroy
- CERPOP, Inserm, Université de Toulouse, Université Paul Sabatier, Toulouse
- Valériane Leroy and Déborah Hirt have contributed equally to the work
| | - Déborah Hirt
- Paris Descartes University, EA 7323
- Clinical Pharmacology Department, AP-HP, Paris Centre Hospital Group, Paris
- Inserm 1018 CESP, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
- Valériane Leroy and Déborah Hirt have contributed equally to the work
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Mwau M, Syeunda CA, Adhiambo M, Bwana P, Kithinji L, Mwende J, Oyiengo L, Sirengo M, Boeke CE. Scale-up of Kenya's national HIV viral load program: Findings and lessons learned. PLoS One 2018; 13:e0190659. [PMID: 29324811 PMCID: PMC5764307 DOI: 10.1371/journal.pone.0190659] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/17/2017] [Indexed: 12/01/2022] Open
Abstract
Objectives Kenya is one of the first African countries to scale up a national HIV viral load monitoring program. We sought to assess program scale up using the national database and identify areas for systems strengthening. Methods Data from January 2012 to March 2016 were extracted from Kenya’s national viral load database. Characteristics of 1,108,356 tests were assessed over time, including reason for testing, turnaround times, test results, treatment regimens, and socio-demographic information. Results The number of facilities offering viral load testing increased to ~2,000 with >40,000 tests being conducted per month by 2016. By March 2016, most (84.2%) tests were conducted for routine monitoring purposes and the turnaround time from facility-level sample collection to result dispatch from the lab was 21(24) [median (IQR)] days. Although the proportions of repeat viral load tests increased over time, the volumes were lower than expected. Elevated viral load was much more common in pediatric and adolescent patients (0-<3 years: 43.1%, 3-<10 years: 34.5%, 10-<20 years: 36.6%) than in adults (30-<60 years: 13.3%; p<0.001). Conclusions Coverage of viral load testing dramatically increased in Kenya to >50% of patients on antiretroviral therapy (ART) by early 2016 and represents a relatively efficient laboratory system. However, strengthening of patient tracking mechanisms and viral load result utilization may be necessary to further improve the system. Additional focus is needed on paediatric/adolescent patients to improve viral suppression in these groups. Kenya’s national viral load database has demonstrated its usefulness in assessing laboratory programs, tracking trends in patient characteristics, monitoring scale-up of new policies and programs, and identifying problem areas for further investigation.
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Affiliation(s)
- Matilu Mwau
- Kenya Medical Research Institute, Nairobi, Kenya
| | | | | | - Priska Bwana
- Kenya Medical Research Institute, Nairobi, Kenya
| | | | - Joy Mwende
- Kenya Medical Research Institute, Nairobi, Kenya
| | - Laura Oyiengo
- National AIDS and STIs Control Program, Ministry of Health, Kenya, Nairobi, Kenya
| | - Martin Sirengo
- National AIDS and STIs Control Program, Ministry of Health, Kenya, Nairobi, Kenya
| | - Caroline E. Boeke
- Independent Researcher, New York, New York, United States of America
- * E-mail:
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Cressey TR, Punyawudho B, Le Coeur S, Jourdain G, Saenjum C, Capparelli E, Jittayanun K, Phanomcheong S, Luvira A, Borkird T, Puangsombat A, Aarons L, Sukrakanchana PO, Urien S, Lallemant M. Assessment of Nevirapine Prophylactic and Therapeutic Dosing Regimens for Neonates. J Acquir Immune Defic Syndr 2017; 75:554-560. [PMID: 28489732 PMCID: PMC5508655 DOI: 10.1097/qai.0000000000001447] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Nevirapine (NVP) is a key component of antiretroviral prophylaxis and treatment for neonates. We evaluated current World Health Organization (WHO) weight-band NVP prophylactic dosing recommendations and investigated optimal therapeutic NVP dosing for neonates. METHODS The PHPT-5 study in Thailand assessed the efficacy of "Perinatal Antiretroviral Intensification" to prevent mother-to-child transmission of HIV in women with <8 weeks of antiretroviral treatment before delivery (NCT01511237). Infants received a 2-week course of zidovudine/lamivudine/NVP (NVP syrup/once daily: 2 mg/kg for 7 days; then 4 mg/kg for 7 days). Infant samples were assessed during the first 2 weeks of life. NVP population pharmacokinetics (PK) parameters were estimated using nonlinear mixed-effects models. Simulations were performed to estimate the probability of achieving target NVP trough concentrations for prophylaxis (>0.10 mg/L) and for therapeutic efficacy (>3.0 mg/L) using different infant dosing strategies. RESULTS Sixty infants (55% male) were included. At birth, median (range) weight was 2.9 (2.3-3.6) kg. NVP concentrations were best described by a 1-compartment PK model. Infant weight and postnatal age influenced NVP PK parameters. Based on simulations for a 3-kg infant, ≥92% would have an NVP trough >0.1 mg/L after 48 hours through 2 weeks using the PHPT-5 and WHO-dosing regimens. For NVP-based therapy, a 6-mg/kg twice daily dose produced a trough >3.0 mg/L in 87% of infants at 48 hours and 80% at 2 weeks. CONCLUSION WHO weight-band prophylactic guidelines achieved target concentrations. Starting NVP 6 mg/kg twice daily from birth is expected to achieve therapeutic concentrations during the first 2 weeks of life.
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Affiliation(s)
- Tim R. Cressey
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Department of Molecular & Clinical Pharmacology, University of Liverpool, UK
| | - Baralee Punyawudho
- Department of Pharmaceutical Care, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
| | - Sophie Le Coeur
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Institut d’Etudes Démographiques, Paris, France
| | - Gonzague Jourdain
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Institut de Recherche pour le Développement (IRD) UMI 174-PHPT, Marseille, France
| | - Chalermpong Saenjum
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Thailand
| | | | - Kanokwan Jittayanun
- Pediatric Department, Health Promotion Center Region 10, Chiang Mai, Thailand
| | | | - Anita Luvira
- Pediatric Department, Nopparat Rajathanee Hospital
| | | | | | - Leon Aarons
- Manchester Pharmacy School, The University of Manchester, Manchester, UK
| | | | - Saik Urien
- EAU7323 Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Marc Lallemant
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Institut de Recherche pour le Développement (IRD) UMI 174-PHPT, Marseille, France
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Bienczak A, Cook A, Wiesner L, Mulenga V, Kityo C, Kekitiinwa A, Walker AS, Owen A, Gibb DM, Burger D, McIlleron H, Denti P. Effect of diurnal variation, CYP2B6 genotype and age on the pharmacokinetics of nevirapine in African children. J Antimicrob Chemother 2017; 72:190-199. [PMID: 27707991 PMCID: PMC5161049 DOI: 10.1093/jac/dkw388] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES To characterize the effects of CYP2B6 polymorphisms, diurnal variation and demographic factors on nevirapine pharmacokinetics in African children. METHODS Non-linear mixed-effects modelling conducted in NONMEM 7.3 described nevirapine plasma concentration-time data from 414 children aged 0.3-15 years. RESULTS Nevirapine pharmacokinetics was best described using a one-compartment disposition model with elimination through a well-stirred liver model accounting for a first-pass effect and transit-compartment absorption. Intrinsic clearance was affected by diurnal variation (characterized using a cosine function with peak amplitude 29% at 12 noon) and CYP2B6 metabolizer status [extensive metabolizer (EM) 516GG|983TT, reference; intermediate metabolizer (IM) 516GT|983TT or 516GG|983TC, 17% lower; slow metabolizer (SM) 516TT|983TT or 516GT|983TC, 50% lower; ultra-slow metabolizer (USM) 516GG|983CC, 68% lower]. Age was found to affect pre-hepatic bioavailability: 31.7% lower at birth and increasing exponentially. Median (90% CI) evening Cmin values in the different metabolizer groups were 5.01 (3.01-7.47), 6.55 (3.65-13.32), 11.59 (5.44-22.71) and 12.32 (12.32-27.25) mg/L, respectively. Evening Cmin values were <3 mg/L in 43% of EM weighing <6 kg and 26% of IM weighing <6 kg, while 73% of SM and 88% of USM in all weight-bands had evening Cmin values >8 mg/L. Cmin was not markedly affected by administration time, but was altered by unequal splitting of the daily dose. CONCLUSIONS Diurnal variation does not greatly affect nevirapine exposure. However, when daily doses cannot be split equally, the larger dose should be given in the morning. To achieve homogeneous exposures, nevirapine doses for SM and USM should be reduced by 50%, and children weighing <6 kg with EM or IM metabolizer status should receive the same dose as children weighing 6-10 kg.
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Affiliation(s)
- Andrzej Bienczak
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Adrian Cook
- MRC Clinical Trials Unit at University College London, London, UK
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Veronica Mulenga
- Department of Paediatrics and Child Health, University Teaching Hospital, Lusaka, Zambia
| | - Cissy Kityo
- Joint Clinical Research Centre, Kampala, Uganda
| | - Addy Kekitiinwa
- Baylor College of Medicine Bristol-Myers Squibb Children's Clinical Centre of Excellence, Kampala, Uganda/Gulu Regional Centre of Excellence, Gulu, Uganda
| | - A Sarah Walker
- MRC Clinical Trials Unit at University College London, London, UK
| | - Andrew Owen
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Diana M Gibb
- MRC Clinical Trials Unit at University College London, London, UK
| | - David Burger
- Department of Pharmacy, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Paolo Denti
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
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Olagunju A, Amara A, Waitt C, Else L, Penchala SD, Bolaji O, Soyinka J, Siccardi M, Back D, Owen A, Khoo S. Validation and clinical application of a method to quantify nevirapine in dried blood spots and dried breast-milk spots. J Antimicrob Chemother 2015; 70:2816-22. [PMID: 26108608 DOI: 10.1093/jac/dkv174] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 05/31/2015] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVES The validation and clinical application of an LC-MS/MS method for the quantification of nevirapine in dried blood spots (DBS) and dried breast-milk spots (DBMS) are presented. METHODS DBS and DBMS were prepared from 50 and 30 μL of nevirapine-spiked whole blood and human breast milk, respectively. Chromatographic separation was achieved on a reverse-phase C18 column with 0.1% formic acid in water/acetonitrile using a solvent gradient programme at a flow rate of 400 μL/min, and detection was by a TSQ Quantum Access triple quadrupole mass spectrometer. The clinical application was evaluated in HIV-positive nursing mothers and their breastfed infants. RESULTS The assay was validated over the concentration range 50-10,000 ng/mL. Accuracy ranged from 93.3% to 113.4% and precision ranged from 1.9% to 12.0%. The mean (percentage coefficient of variation) recovery of nevirapine from DBS and DBMS was ≥ 70.7% (≤ 8.2) and the matrix effect was ≤ 1.04 (≤ 6.1). Nevirapine was stable in DBS and DBMS for ≥ 15 months at room temperature and -80°C. Mean (SD) AUC0-12, Cmax and Cmin in maternal plasma versus breast milk were 57,808 ng · h/mL (24,315) versus 55,817 ng · h/mL (22,368), 6140 ng/mL (2605) versus 5231 ng/mL (2215) and 4334 ng/mL (1880) versus 4342 ng/mL (2245), respectively. The milk-to-plasma concentration ratio over the dosing interval was 0.94 (0.15). Infant plasma concentrations 2 and 8 h after maternal dosing were 580.6 ng/mL (464.7-1607) and 584.1 ng/mL (381.5-1570), respectively. CONCLUSIONS These methods further extend opportunities for conducting clinical pharmacokinetic studies in nursing mother-infant pairs, especially in resource-limited settings.
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Affiliation(s)
- Adeniyi Olagunju
- Department of Molecular and Clinical Pharmacology, University of Liverpool, 70 Pembroke Place, Liverpool L69 3GF, UK Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Alieu Amara
- Liverpool Bioanalytical Facility, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GA, UK
| | - Catriona Waitt
- Department of Molecular and Clinical Pharmacology, University of Liverpool, 70 Pembroke Place, Liverpool L69 3GF, UK
| | - Laura Else
- Liverpool Bioanalytical Facility, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GA, UK
| | - Sujan D Penchala
- Liverpool Bioanalytical Facility, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool L69 3GA, UK
| | - Oluseye Bolaji
- Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Julius Soyinka
- Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Marco Siccardi
- Department of Molecular and Clinical Pharmacology, University of Liverpool, 70 Pembroke Place, Liverpool L69 3GF, UK
| | - David Back
- Department of Molecular and Clinical Pharmacology, University of Liverpool, 70 Pembroke Place, Liverpool L69 3GF, UK
| | - Andrew Owen
- Department of Molecular and Clinical Pharmacology, University of Liverpool, 70 Pembroke Place, Liverpool L69 3GF, UK
| | - Saye Khoo
- Department of Molecular and Clinical Pharmacology, University of Liverpool, 70 Pembroke Place, Liverpool L69 3GF, UK
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Safety and efficacy of darunavir/ritonavir in treatment-experienced pediatric patients: week 48 results of the ARIEL trial. Pediatr Infect Dis J 2015; 34:e132-7. [PMID: 25719453 DOI: 10.1097/inf.0000000000000644] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND ARIEL (Darunavir in treatment-experienced pediatric population) was a phase II, open-label study assessing safety and antiviral activity of darunavir/ritonavir twice daily with an optimized background regimen (OBR) in treatment-experienced, HIV-1-infected pediatric patients (3 to <6 years, weighing 10 to <20 kg). METHODS The study consisted of an initial 4-week screening period, 48 weeks of treatment and a 4-week follow-up period. Patients initially received darunavir/ritonavir 20/3 mg/kg twice-daily for 2 weeks. Following review of pharmacokinetic, safety and antiviral data, the doses of darunavir/ritonavir were adjusted to 25/3 mg/kg twice-daily for patients <15 kg, and 375/50 mg twice-daily for patients 15 to <20 kg. RESULTS Of the 34 patients screened, 21 were treated (median treatment duration 48.6 weeks). Darunavir plus an OBR was well tolerated over 48 weeks, with no new safety concerns, and a comparable safety profile to that seen in older children and adults. All treatment-emergent lipid-related and glucose-related laboratory abnormalities were grade 1 or 2. At week 48, 17 of 21 patients (81.0%) had a confirmed virologic response (intent-to-treat, time-to-loss of virologic response). Improvements in height and weight were seen during the study. CONCLUSIONS No new safety concerns were observed over a 48 week period. These results led to lowering the age to 3 years at which darunavir/ritonavir is indicated for use in treatment-experienced pediatric patients. This study also established doses of darunavir to use in treatment-experienced, HIV-1-infected patients aged 3 to <6 years. A high virologic response was observed with this dose. No development of resistance was observed in patients who experienced virologic failure.
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Impact of adherence and anthropometric characteristics on nevirapine pharmacokinetics and exposure among HIV-infected Kenyan children. J Acquir Immune Defic Syndr 2014; 67:277-86. [PMID: 25140906 DOI: 10.1097/qai.0000000000000300] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND There are insufficient data on pediatric antiretroviral therapy (ART) pharmacokinetics (PK), particularly for children in low- and middle-income countries. METHODS We conducted a prospective nevirapine (NVP) PK study among HIV-infected Kenyan children aged 3-13 years initiating an NVP-based ART regimen. NVP dose timing was measured through medication event monitors. Participants underwent 2 inpatient assessments: 1 at 4-8 weeks after ART initiation and 1 at 3-4 months after ART initiation. Allometric scaling of oral clearance (CL)/bioavailability (F) and volume of distribution (Vd)/F values were computed. Nonlinear mixed-effects modeling using the first-order conditional estimation with interaction method was performed with covariates. The impact of adherence on time below minimum effective concentration was assessed in the final PK model using medication event monitors data and model-estimated individual parameters. RESULTS Among 21 children enrolled, mean age was 5.4 years and 57% were female. CL/F was 1.67 L/h and Vd/F was 3.8 L for a median child weighing 15 kg. Participants' age had a significant impact on CL/F (P < 0.05), with an estimated decrease in CL of 6.2% for each 1-year increase in age. Total body water percentage was significantly associated with Vd/F (P < 0.001). No children had >10% of time below minimum effective concentration when the PK model assumed perfect adherence compared with 10 children when adherence data were used. CONCLUSIONS Age and body composition were significantly associated with children's NVP PK parameters. ART adherence significantly impacted drug exposure over time, revealing subtherapeutic windows that may lead to viral resistance.
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