1
|
Engelbrecht AE, Wiesner L, Norman J, Rabie H, Decloedt EH. Pediatric Antiretroviral Therapeutic Drug Monitoring: A Five and a Half Year Experience from a South African Tertiary Hospital. J Trop Pediatr 2020; 66:385-394. [PMID: 31754710 DOI: 10.1093/tropej/fmz077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Antiretroviral therapeutic drug monitoring (TDM) is not routinely used in the management of human immunodeficiency virus, but may be useful in pediatric patients who are prone to altered pharmacokinetics. Data on the routine use of antiretroviral TDM in pediatrics are sparse especially data from sub-Saharan Africa. METHODS We retrospectively reviewed the antiretroviral TDM indications at Tygerberg Children's Hospital, identified pediatric patients who had antiretroviral TDM requests from January 2012 until June 2017 and reviewed their clinical records. RESULTS Fifty-nine patients were identified who presented with 64 clinical problems for which TDM was requested. TDM was requested for lopinavir, efavirenz and nevirapine in 83% (53/64), 14% (9/64) and 3% (2/64) of clinical problems, respectively. Lopinavir was mostly requested in patients when adherence measures did not correlate with the clinical picture, suspected non-adherence, lopinavir-rifampicin interactions and for neonatal safety monitoring. Efavirenz was requested when toxicity was suspected and nevirapine in patients receiving rifampicin. Lopinavir TDM confirmed non-adherence in 25% (4/16) of cases when adherence measures did not correlate with the clinical picture and in 43% (3/7) of cases when non-adherence was suspected by the clinician. Efavirenz TDM confirmed toxicity in 100% (6/6) of patients. CONCLUSIONS Lopinavir TDM was mostly requested when adherence measures did not correlate with the clinical picture, when rifampicin was co-administered and for perinatal safety monitoring. Lopinavir TDM excluded pharmacokinetic reasons for failure in patients failing treatment when lopinavir dosing was supervised. Efavirenz TDM was requested for suspected toxicity with a 100% positive predictive value.
Collapse
Affiliation(s)
- Anton E Engelbrecht
- Division of Clinical Pharmacology, Department of Medicine, Stellenbosch University, Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Jennifer Norman
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Helena Rabie
- Division of Infectious Diseases, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - Eric H Decloedt
- Division of Clinical Pharmacology, Department of Medicine, Stellenbosch University, Cape Town, South Africa
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Punyawudho B, Singkham N, Thammajaruk N, Dalodom T, Kerr SJ, Burger DM, Ruxrungtham K. Therapeutic drug monitoring of antiretroviral drugs in HIV-infected patients. Expert Rev Clin Pharmacol 2016; 9:1583-1595. [PMID: 27626677 DOI: 10.1080/17512433.2016.1235972] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Therapeutic drug monitoring (TDM) may be beneficial when applied to antiretroviral (ARV). Even though TDM can be a valuable strategy in HIV management, its role remains controversial. Areas covered: This review provides a comprehensive update on important issues relating to TDM of ARV drugs in HIV-infected patients. Articles from PubMed with keywords relevant to each topic section were reviewed. Search strategies limited to articles published in English. Expert commentary: There is evidence supporting the use of TDM in HIV treatment. However, some limitations need to be considered. The evidence supporting the use of routine TDM for all patients is limited, as it is not clear that this strategy offers any advantages over TDM for selected indications. Selected groups of patients including patients with physiological changes, patients with drug-drug interactions or toxicity, and the elderly could potentially benefit from TDM, as optimized dosing is challenging in these populations.
Collapse
Affiliation(s)
- Baralee Punyawudho
- a Department of Pharmaceutical Care, Faculty of Pharmacy , Chiang Mai University , Chiang Mai , Thailand
| | - Noppaket Singkham
- a Department of Pharmaceutical Care, Faculty of Pharmacy , Chiang Mai University , Chiang Mai , Thailand
| | | | - Theera Dalodom
- b HIV-NAT , Thai Red Cross AIDS Research Centre , Bangkok , Thailand
| | - Stephen J Kerr
- b HIV-NAT , Thai Red Cross AIDS Research Centre , Bangkok , Thailand.,c The Kirby Institute, University of New South Wales , Sydney , Australia.,d Department of Global Health, Academic Medical Center , University of Amsterdam, Amsterdam Institute for Global Health and Development , Amsterdam , The Netherlands
| | - David M Burger
- e Radbound University Medical Center , Nijmegen , The Netherlands
| | - Kiat Ruxrungtham
- b HIV-NAT , Thai Red Cross AIDS Research Centre , Bangkok , Thailand.,f Faculty of Medicine , Chulalongkorn University , Bangkok , Thailand
| |
Collapse
|
4
|
Moretton MA, Cohen L, Lepera L, Bernabeu E, Taira C, Höcht C, Chiappetta DA. Enhanced oral bioavailability of nevirapine within micellar nanocarriers compared with Viramune ®. Colloids Surf B Biointerfaces 2014; 122:56-65. [DOI: 10.1016/j.colsurfb.2014.06.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/25/2014] [Accepted: 06/20/2014] [Indexed: 01/28/2023]
|
5
|
Kern SE. Challenges in conducting clinical trials in children: approaches for improving performance. Expert Rev Clin Pharmacol 2014; 2:609-617. [PMID: 20228942 DOI: 10.1586/ecp.09.40] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Recent legislative changes in both Europe and the USA have increased the responsibility of drug developers to purposefully study the agents they market in children so that specific dosing recommendations can be made to assist clinicians in their use. Typically, clinicians use empiricalor experiential-based rationales for selecting the dose to use in children, generally in a manner that attempts to achieve the same dose-exposure or pharmacokinetic profile in children as in adults. However, whether this approach achieves the necessary dose exposure or exposure effect needed may not be systematically explored during off-label use. This creates the opportunity for under- or over-exposure in children, particularly in very young children (i.e., less than 2 years old) where a combination of factors during development can effect both pharmacokinetics and pharmacodynamics. The ethical, physiological and statistical differences of studying new therapeutic agents in children present economic challenges that may create unintended incentives - both positive and negative - for any individual developer who tries to meet the requirements of new legislation to study pharmaceutical agents in children. There should be a continued emphasis in academic clinical pharmacology programs towards creative methods and approaches to better understand these differences in children compared with adults. The ability to use information from knowledge obtained from adult studies, from preclinical studies, from studies of compounds with similar chemistry or pharmacology, or from known physiological differences between children and adults is essential to choosing a suitable dose for children and achieving these regulatory aims.
Collapse
Affiliation(s)
- Steven E Kern
- Associate Professor of Pharmaceutics and Pharmaceutical Chemistry, Adjunct Associate Professor of Pediatrics and Anesthesiology, Research Associate Professor of Bioengineering, University of Utah, Salt Lake City, UT, USA, Tel.: +1 801 585 5958, ,
| |
Collapse
|
6
|
Kwara A, Ramachandran G, Swaminathan S. Dose adjustment of the non-nucleoside reverse transcriptase inhibitors during concurrent rifampicin-containing tuberculosis therapy: one size does not fit all. Expert Opin Drug Metab Toxicol 2010; 6:55-68. [PMID: 19968575 DOI: 10.1517/17425250903393752] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
IMPORTANCE OF THE FIELD HIV/tuberculosis (TB) co-infection is common and associated with high mortality. Simultaneous highly active antiretroviral therapy during TB treatment is associated with substantial survival benefit but drug-drug interactions complicate NNRTI dosing. AREAS COVERED IN THIS REVIEW We reviewed the impact of rifampicin-containing TB therapy on the NNRTIs pharmacokinetics and clinical outcome. PubMed database was searched from 1966 to July 2009 using the terms efavirenz, rifampicin, nevirapine, pharmacokinetics, pharmacogenetics, HIV, TB, CYP2B6, CYP3A4 and metabolism. References from identified articles and abstracts from meetings were also reviewed. WHAT THE READER WILL GAIN A comprehensive review of the literature on this subject including pharmacokinetic and clinical studies. Most studies were small, observational or underpowered to detect the true effect of rifampicin on NNRTI-based therapy. None of the studies were controlled for genetic factors and there were limited data on children. TAKE HOME MESSAGE There were insufficient data to make definitive recommendations about dose adjustment of the NNRTIs during rifampin-containing therapy. Current data suggest that the standard dose of efavirenz or nevirapine is adequate in most HIV/TB co-infected adults. However, more research is needed in pediatric populations as well as to define role of drug-gene interactions.
Collapse
Affiliation(s)
- Awewura Kwara
- Warren Alpert Medical School of Brown University and The Miriam Hospital, Providence, Rhode Island 02906, USA.
| | | | | |
Collapse
|