title: The influence of nevirapine and efavirenz-based anti-retroviral therapy on the pharmacokinetics of lumefantrine and anti-malarial dose recommendation in HIV-malaria co-treatment.
abstract: BACKGROUND
  HIV-malaria co-infected patients in most parts of sub-Saharan Africa are treated with both artemether-lumefantrine (AL) and efavirenz (EFV) or nevirapine (NVP)-based antiretroviral therapy (ART). EFV, NVP, artemether and lumefantrine are substrates, inhibitors or inducers of CYP3A4 and CYP2B6, creating a potential for drug-drug interactions. The effect of EFV and/or NVP on lumefantrine pharmacokinetic profile among HIV-malaria co-infected patients on ART and treated with AL was investigated. Optimal lumefantrine dosage regimen for patients on EFV-based ART was determined by population pharmacokinetics and simulation.
  
  
  METHODS
  This was a non-randomized, open label, parallel, prospective cohort study in which 128, 66 and 75 HIV-malaria co-infected patients on NVP-based ART (NVP-arm), EFV-based ART (EFV-arm) and ART naïve (control-am) were enrolled, respectively. Patients were treated with AL and contributed sparse venous plasma samples. Pharmacokinetic analysis of lumefantrine was done using non-linear mixed effect modelling.
  
  
  RESULTS
  Of the evaluated models, a two-compartment pharmacokinetic model with first order absorption and lag-time described well lumefantrine plasma concentrations time profile. Patients in the EFV-arm but not in the NVP-arm had significantly lower lumefantrine bioavailability compared to that in the control-arm. Equally, 32% of patients in the EFV-arm had day-7 lumefantrine plasma concentrations below 280 ng/ml compared to only 4% in the control-arm and 3% in the NVP-arm. Upon post hoc simulation of lumefantrine exposure, patients in the EFV-arm had lower exposure (median (IQR)) compared to that in the control-arm; AUC0-inf; was 303,130 (211,080-431,962) versus 784,830 (547,405-1,116,250); day-7 lumefantrine plasma concentrations was: 335.5 (215.8-519.5) versus 858.7 (562.3-1,333.8), respectively. The predictive model through simulation of lumefantrine exposure at different dosage regimen scenarios for patients on EFV-based ART, suggest that AL taken twice daily for five days using the current dose could improve lumefantrine exposure and consequently malaria treatment outcomes.
  
  
  CONCLUSIONS
  Co-treatment of AL with EFV-based ART but not NVP-based ART significantly reduces lumefantrine bioavailability and consequently total exposure. To ensure adequate lumefantrine exposure and malaria treatment success in HIV-malaria co-infected patients on EFV-based ART, an extension of the duration of AL treatment to five days using the current dose is proposed.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, PO Box 65013, Dar es Salaam, Tanzania. bettynjau7@gmail.com.|Division of Clinical Pharmacology, Karolinska Institutet, Karolinska University Hospital, C-168, SE- 141 86, Stockholm, Sweden. bettynjau7@gmail.com.
authors.forename: Betty A
authors.initials: BA
authors.lastname: Maganda
authors.affiliation: Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, PO Box 65013, Dar es Salaam, Tanzania. engaimisi@gmail.com.
authors.forename: Eliford
authors.initials: E
authors.lastname: Ngaimisi
authors.affiliation: Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, PO Box 65013, Dar es Salaam, Tanzania. enali2012@gmail.com.
authors.forename: Appolinary A R
authors.initials: AA
authors.lastname: Kamuhabwa
authors.affiliation: Division of Clinical Pharmacology, Karolinska Institutet, Karolinska University Hospital, C-168, SE- 141 86, Stockholm, Sweden. eleni.aklillu@ki.se.
authors.forename: Eleni
authors.initials: E
authors.lastname: Aklillu
authors.affiliation: Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, PO Box 65013, Dar es Salaam, Tanzania. Minziobejayesu@gmail.com.
authors.forename: Omary M S
authors.initials: OM
authors.lastname: Minzi
mesh_terms: D000328:Adult; D000368:Aged; D000480:Alkynes; D044966:Anti-Retroviral Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D000962:Antimalarials / Q000493:pharmacokinetics*; D048588:Benzoxazines / Q000493:pharmacokinetics*; D003521:Cyclopropanes; D004347:Drug Interactions; D004983:Ethanolamines / Q000493:pharmacokinetics*; D005260:Female; D005449:Fluorenes / Q000493:pharmacokinetics*; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D000078102:Lumefantrine; D008288:Malaria / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D019829:Nevirapine / Q000493:pharmacokinetics*; D011446:Prospective Studies; D013636:Tanzania; D055815:Young Adult
chemical_list: D000480:Alkynes; D044966:Anti-Retroviral Agents; D000962:Antimalarials; D048588:Benzoxazines; D003521:Cyclopropanes; D004983:Ethanolamines; D005449:Fluorenes; D019829:Nevirapine; D000078102:Lumefantrine; C098320:efavirenz