The impact of CYP2B6 polymorphisms on the interactions of efavirenz with lumefantrine: Implications for paediatric antimalarial therapy

Zaril Harza Zakaria, Raj K.S. Badhan

Research output: Contribution to journalArticle

Abstract

Lumefantrine is a widely used antimalarial in children in sub-Saharan Africa and is predominantly metabolised by CYP3A4. The concomitant use of lumefantrine with the antiretroviral efavirenz, which is metabolised by CYP2B6 and is an inducer of CYP3A4, increases the risk of lumefantrine failure and can result in an increased recrudescence rate in HIV-infected children. This is further confounded by CYP2B6 being highly polymorphic resulting in a 2–3 fold higher efavirenz plasma concentration in polymorphic subjects, which enhances the potential for an efavirenz-lumefantrine drug-drug interaction (DDI). This study developed a population-based PBPK model capable of predicting the impact of efavirenz-mediated DDIs on lumefantrine pharmacokinetics in African paediatric population groups, which also considered the polymorphic nature of CYP2B6. The validated model demonstrated a significant difference in lumefantrine target day 7 concentrations (Cd7) in the presence and absence of efavirenz and confirmed the capability of efavirenz to initiate this DDI. This was more apparent in the *6/*6 compared to *1/*1 population group and resulted in a significantly lower (P < 0.001) lumefantrine Cd7. A prospective change in dosing schedule from 3-days to 7-days resulted in a greater number of *6/*6 subjects (28–57%) attaining the target Cd7 across age bands (0.25–13 years), with the greatest increase evident in the 1–4 year old group (3-day: 1%; 7-day: 28%).
LanguageEnglish
Pages90-101
JournalEuropean Journal of Pharmaceutical Sciences
Volume119
Early online date7 Apr 2018
DOIs
Publication statusE-pub ahead of print - 7 Apr 2018

Fingerprint

efavirenz
Antimalarials
Pediatrics
Cytochrome P-450 CYP3A
Drug Interactions
Population Groups
Therapeutics
Africa South of the Sahara
lumefantrine
Cytochrome P-450 CYP2B6
Pharmaceutical Preparations
Appointments and Schedules

Bibliographical note

© 2018, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/


The authors would like to thank the Ministry of Health Malaysia for providing funding for this project.

Keywords

  • Physiologically-based pharmacokinetics
  • Malaria
  • HIV
  • Paediatrics
  • Africa

Cite this

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title = "The impact of CYP2B6 polymorphisms on the interactions of efavirenz with lumefantrine: Implications for paediatric antimalarial therapy",
abstract = "Lumefantrine is a widely used antimalarial in children in sub-Saharan Africa and is predominantly metabolised by CYP3A4. The concomitant use of lumefantrine with the antiretroviral efavirenz, which is metabolised by CYP2B6 and is an inducer of CYP3A4, increases the risk of lumefantrine failure and can result in an increased recrudescence rate in HIV-infected children. This is further confounded by CYP2B6 being highly polymorphic resulting in a 2–3 fold higher efavirenz plasma concentration in polymorphic subjects, which enhances the potential for an efavirenz-lumefantrine drug-drug interaction (DDI). This study developed a population-based PBPK model capable of predicting the impact of efavirenz-mediated DDIs on lumefantrine pharmacokinetics in African paediatric population groups, which also considered the polymorphic nature of CYP2B6. The validated model demonstrated a significant difference in lumefantrine target day 7 concentrations (Cd7) in the presence and absence of efavirenz and confirmed the capability of efavirenz to initiate this DDI. This was more apparent in the *6/*6 compared to *1/*1 population group and resulted in a significantly lower (P < 0.001) lumefantrine Cd7. A prospective change in dosing schedule from 3-days to 7-days resulted in a greater number of *6/*6 subjects (28–57{\%}) attaining the target Cd7 across age bands (0.25–13 years), with the greatest increase evident in the 1–4 year old group (3-day: 1{\%}; 7-day: 28{\%}).",
keywords = "Physiologically-based pharmacokinetics, Malaria, HIV, Paediatrics, Africa",
author = "Zakaria, {Zaril Harza} and Badhan, {Raj K.S.}",
note = "{\circledC} 2018, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ The authors would like to thank the Ministry of Health Malaysia for providing funding for this project.",
year = "2018",
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doi = "10.1016/j.ejps.2018.04.012",
language = "English",
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journal = "European Journal of Pharmaceutical Sciences",
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T1 - The impact of CYP2B6 polymorphisms on the interactions of efavirenz with lumefantrine

T2 - European Journal of Pharmaceutical Sciences

AU - Zakaria, Zaril Harza

AU - Badhan, Raj K.S.

N1 - © 2018, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ The authors would like to thank the Ministry of Health Malaysia for providing funding for this project.

PY - 2018/4/7

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N2 - Lumefantrine is a widely used antimalarial in children in sub-Saharan Africa and is predominantly metabolised by CYP3A4. The concomitant use of lumefantrine with the antiretroviral efavirenz, which is metabolised by CYP2B6 and is an inducer of CYP3A4, increases the risk of lumefantrine failure and can result in an increased recrudescence rate in HIV-infected children. This is further confounded by CYP2B6 being highly polymorphic resulting in a 2–3 fold higher efavirenz plasma concentration in polymorphic subjects, which enhances the potential for an efavirenz-lumefantrine drug-drug interaction (DDI). This study developed a population-based PBPK model capable of predicting the impact of efavirenz-mediated DDIs on lumefantrine pharmacokinetics in African paediatric population groups, which also considered the polymorphic nature of CYP2B6. The validated model demonstrated a significant difference in lumefantrine target day 7 concentrations (Cd7) in the presence and absence of efavirenz and confirmed the capability of efavirenz to initiate this DDI. This was more apparent in the *6/*6 compared to *1/*1 population group and resulted in a significantly lower (P < 0.001) lumefantrine Cd7. A prospective change in dosing schedule from 3-days to 7-days resulted in a greater number of *6/*6 subjects (28–57%) attaining the target Cd7 across age bands (0.25–13 years), with the greatest increase evident in the 1–4 year old group (3-day: 1%; 7-day: 28%).

AB - Lumefantrine is a widely used antimalarial in children in sub-Saharan Africa and is predominantly metabolised by CYP3A4. The concomitant use of lumefantrine with the antiretroviral efavirenz, which is metabolised by CYP2B6 and is an inducer of CYP3A4, increases the risk of lumefantrine failure and can result in an increased recrudescence rate in HIV-infected children. This is further confounded by CYP2B6 being highly polymorphic resulting in a 2–3 fold higher efavirenz plasma concentration in polymorphic subjects, which enhances the potential for an efavirenz-lumefantrine drug-drug interaction (DDI). This study developed a population-based PBPK model capable of predicting the impact of efavirenz-mediated DDIs on lumefantrine pharmacokinetics in African paediatric population groups, which also considered the polymorphic nature of CYP2B6. The validated model demonstrated a significant difference in lumefantrine target day 7 concentrations (Cd7) in the presence and absence of efavirenz and confirmed the capability of efavirenz to initiate this DDI. This was more apparent in the *6/*6 compared to *1/*1 population group and resulted in a significantly lower (P < 0.001) lumefantrine Cd7. A prospective change in dosing schedule from 3-days to 7-days resulted in a greater number of *6/*6 subjects (28–57%) attaining the target Cd7 across age bands (0.25–13 years), with the greatest increase evident in the 1–4 year old group (3-day: 1%; 7-day: 28%).

KW - Physiologically-based pharmacokinetics

KW - Malaria

KW - HIV

KW - Paediatrics

KW - Africa

UR - https://www.sciencedirect.com/science/article/pii/S0928098718301696

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M3 - Article

VL - 119

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JO - European Journal of Pharmaceutical Sciences

JF - European Journal of Pharmaceutical Sciences

SN - 0928-0987

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