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Nakijoba R, Nakayiwa Kawuma A, Ojara FW, Tabwenda JC, Kyeyune J, Turyahabwe C, Asiimwe SP, Magoola J, Banda CG, Castelnuovo B, Buzibye A, Waitt C. -Pharmacokinetics of antimalarial drugs used to treat uncomplicated malaria in breastfeeding mother-infant pairs: An observational pharmacokinetic study. Wellcome Open Res 2023; 8:12. [PMID: 37744730 PMCID: PMC10514676 DOI: 10.12688/wellcomeopenres.18512.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2023] [Indexed: 09/26/2023] Open
Abstract
Background: Data surrounding the exposure of the breastfed infant to drugs and any associated risks are sparse. Drugs usually are transferred to milk in small quantities, and many have been used without obviously noticeable infant toxicity for many years - this lack of a 'safety signal' has further reduced the interest in studying mother-to-infant transfer of the drugs. In sub-Saharan Africa, pregnant women are at risk of Plasmodium falciparum infection, and one in four women have evidence of placental infection at the time of delivery. Artemisinin-based combination therapies (ACTs), primarily artemether-lumefantrine (AL), are the current first-line treatment for uncomplicated Plasmodium falciparum malaria, with the same dosing recommendations in breastfeeding women as those in the adult population. Dihydroartemisinin-piperaquine (DP) is routinely used as an alternative to AL in Uganda. However, lactation pharmacokinetics (PK) of ACTs are unknown. Pharmacokinetic characterization of anti-malarial transfer to breast milk and breastfed infants is crucial in understanding the potential consequences to the infant, in terms of therapeutic- and prophylactic effects as well as potential toxicity. Methods: This observational study will enroll 30 mother-infant pairs, and aims to characterize the breastmilk transfer of antimalarial medications (AL and DP) to infants when these ACTs are administered to mothers as part of treatment for uncomplicated malaria. In addition, we will assess the mental health of the breastfeeding mothers enrolled as well as the well-being of their children. PK samples of maternal blood, breastmilk and breastfeeding infant's blood will be obtained at specific times points. Pharmacokinetic data will be analyzed using a population pharmacokinetic approach. Conclusions: We anticipate that findings from this research will guide to develop a PK model describing lumefantrine and piperaquine disposition and will provide a framework to foster other lactation pharmacokinetic studies in different disease areas.
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Affiliation(s)
- Ritah Nakijoba
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Aida Nakayiwa Kawuma
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Francis Williams Ojara
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
- Department of Pharmacology and Therapeutics, Gulu University, Gulu, 256, Uganda
| | - Jovia C. Tabwenda
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Jacqueline Kyeyune
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Christine Turyahabwe
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Simon Peter Asiimwe
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Johnson Magoola
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | | | - Barbara Castelnuovo
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Allan Buzibye
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
| | - Catriona Waitt
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, 256, Uganda
- Department of Pharmacology and Therapeutics, University of Liverpool, Liverpool, L69 7BE, UK
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2
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Masserey T, Lee T, Golumbeanu M, Shattock AJ, Kelly SL, Hastings IM, Penny MA. The influence of biological, epidemiological, and treatment factors on the establishment and spread of drug-resistant Plasmodium falciparum. eLife 2022; 11:e77634. [PMID: 35796430 PMCID: PMC9262398 DOI: 10.7554/elife.77634] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 06/22/2022] [Indexed: 11/13/2022] Open
Abstract
The effectiveness of artemisinin-based combination therapies (ACTs) to treat Plasmodium falciparum malaria is threatened by resistance. The complex interplay between sources of selective pressure-treatment properties, biological factors, transmission intensity, and access to treatment-obscures understanding how, when, and why resistance establishes and spreads across different locations. We developed a disease modelling approach with emulator-based global sensitivity analysis to systematically quantify which of these factors drive establishment and spread of drug resistance. Drug resistance was more likely to evolve in low transmission settings due to the lower levels of (i) immunity and (ii) within-host competition between genotypes. Spread of parasites resistant to artemisinin partner drugs depended on the period of low drug concentration (known as the selection window). Spread of partial artemisinin resistance was slowed with prolonged parasite exposure to artemisinin derivatives and accelerated when the parasite was also resistant to the partner drug. Thus, to slow the spread of partial artemisinin resistance, molecular surveillance should be supported to detect resistance to partner drugs and to change ACTs accordingly. Furthermore, implementing more sustainable artemisinin-based therapies will require extending parasite exposure to artemisinin derivatives, and mitigating the selection windows of partner drugs, which could be achieved by including an additional long-acting drug.
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Affiliation(s)
- Thiery Masserey
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Tamsin Lee
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Monica Golumbeanu
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Andrew J Shattock
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Sherrie L Kelly
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Ian M Hastings
- Liverpool School of Tropical MedicineLiverpoolUnited Kingdom
| | - Melissa A Penny
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
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3
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Nhama A, Nhamússua L, Macete E, Bassat Q, Salvador C, Enosse S, Candrinho B, Carvalho E, Nhacolo A, Chidimatembue A, Saifodine A, Zulliger R, Lucchi N, Svigel SS, Moriarty LF, Halsey ES, Mayor A, Aide P. In vivo efficacy and safety of artemether-lumefantrine and amodiaquine-artesunate for uncomplicated Plasmodium falciparum malaria in Mozambique, 2018. Malar J 2021; 20:390. [PMID: 34600544 PMCID: PMC8487544 DOI: 10.1186/s12936-021-03922-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/20/2021] [Indexed: 11/17/2022] Open
Abstract
Background Artemisinin-based combination therapy (ACT) has been the recommended first-line treatment for uncomplicated malaria in Mozambique since 2006, with artemether–lumefantrine (AL) and amodiaquine–artesunate (AS–AQ) as the first choice. To assess efficacy of currently used ACT, an in vivo therapeutic efficacy study was conducted. Methods The study was conducted in four sentinel sites: Montepuez, Moatize, Mopeia and Massinga. Patients between 6 and 59 months old with uncomplicated Plasmodium falciparum malaria (2000–200,000 parasites/µl) were enrolled between February and September of 2018, assigned to either an AL or AS–AQ treatment arm, and monitored for 28 days. A Bayesian algorithm was applied to differentiate recrudescence from new infection using genotyping data of seven neutral microsatellites. Uncorrected and PCR-corrected efficacy results at day 28 were calculated. Results Totals of 368 and 273 patients were enrolled in the AL and AS–AQ arms, respectively. Of these, 9.5% (35/368) and 5.1% (14/273) were lost to follow-up in the AL and AS–AQ arms, respectively. There were 48 and 3 recurrent malaria infections (late clinical and late parasitological failures) in the AL and AS–AQ arms, respectively. The day 28 uncorrected efficacy was 85.6% (95% confidence interval (CI) 81.3–89.2%) for AL and 98.8% (95% CI 96.7–99.8%) for AS–AQ, whereas day 28 PCR-corrected efficacy was 97.9% (95% CI 95.6–99.2%) for AL and 99.6% (95% CI 97.9–100%) for AS–AQ. Molecular testing confirmed that 87.4% (42/48) and 33.3% (1/3) of participants with a recurrent malaria infection in the AL and AS–AQ arms were new infections; an expected finding in a high malaria transmission area. Adverse events were documented in less than 2% of participants for both drugs. Conclusion Both AL and AS–AQ have therapeutic efficacies well above the 90% WHO recommended threshold and remain well-tolerated in Mozambique. Routine monitoring of therapeutic efficacy should continue to ensure the treatments remain efficacious. Trial registration Clinicaltrials.gov: NCT04370977 Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03922-9.
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Affiliation(s)
- Abel Nhama
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,Instituto Nacional de Saúde (INS), Ministério da Saúde, Maputo, Mozambique
| | - Lídia Nhamússua
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Eusébio Macete
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,Direção Nacional de Saúde Pública, Ministério da Saúde, Maputo, Mozambique
| | - Quique Bassat
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,Barcelona Institute for Global Health (ISGlobal), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Crizolgo Salvador
- Instituto Nacional de Saúde (INS), Ministério da Saúde, Maputo, Mozambique
| | - Sónia Enosse
- Instituto Nacional de Saúde (INS), Ministério da Saúde, Maputo, Mozambique
| | - Baltazar Candrinho
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
| | - Eva Carvalho
- World Health Organization, WHO Country Office Maputo, Maputo, Mozambique
| | - Arsénio Nhacolo
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | | | - Abuchahama Saifodine
- United States President's Malaria Initiative, United States Agency for International Development, Maputo, Mozambique
| | - Rose Zulliger
- United States President's Malaria Initiative, Centers for Disease Control and Prevention, Maputo, Mozambique
| | - Naomi Lucchi
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Samaly S Svigel
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Leah F Moriarty
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA.,United States President's Malaria Initiative, Atlanta, GA, USA
| | - Eric S Halsey
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA.,United States President's Malaria Initiative, Atlanta, GA, USA
| | - Alfredo Mayor
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,Barcelona Institute for Global Health (ISGlobal), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique. .,Instituto Nacional de Saúde (INS), Ministério da Saúde, Maputo, Mozambique.
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4
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Coonahan ES, Yang KA, Pecic S, De Vos M, Wellems TE, Fay MP, Andersen JF, Tarning J, Long CA. Structure-switching aptamer sensors for the specific detection of piperaquine and mefloquine. Sci Transl Med 2021; 13:13/585/eabe1535. [PMID: 33731432 DOI: 10.1126/scitranslmed.abe1535] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 02/22/2021] [Indexed: 12/28/2022]
Abstract
Tracking antimalarial drug use and efficacy is essential for monitoring the current spread of antimalarial drug resistance. However, available methods for determining tablet quality and patient drug use are often inaccessible, requiring well-equipped laboratories capable of performing liquid chromatography-mass spectrometry (LC-MS). Here, we report the development of aptamer-based fluorescent sensors for the rapid, specific detection of the antimalarial compounds piperaquine and mefloquine-two slow-clearing partner drugs in current first-line artemisinin-based combination therapies (ACTs). Highly selective DNA aptamers were identified that bind piperaquine and mefloquine with dissociation constants (K d's) measured in the low nanomolar range via two independent methods. The aptamers were isolated from a library of single-stranded DNA molecules using a capture-systematic evolution of ligands by exponential enrichment (SELEX) technique and then adapted into structure-switching aptamer fluorescent sensors. Sensor performance was optimized for the detection of drug from human serum and crushed tablets, resulting in two sensing platforms. The patient sample platform was validated against an LC-MS standard drug detection method in samples from healthy volunteers and patients with malaria. This assay provides a rapid and inexpensive method for tracking antimalarial drug use and quality for the containment and study of parasite resistance, a major priority for malaria elimination campaigns. This sensor platform allows for flexibility of sample matrix and can be easily adapted to detect other small-molecule drugs.
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Affiliation(s)
- Erin S Coonahan
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA.,Institute of Biomedical Engineering, University of Oxford, Oxford OX3 7DQ, UK.,Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Kyung-Ae Yang
- Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Stevan Pecic
- Department of Chemistry and Biochemistry, California State University , Fullerton, CA 92831, USA
| | - Maarten De Vos
- Institute of Biomedical Engineering, University of Oxford, Oxford OX3 7DQ, UK.,Department of Electrical Engineering (ESAT), KU Leuven, Leuven 3000, Belgium.,Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Thomas E Wellems
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA
| | - Michael P Fay
- Biostatistics Research Branch, DCR, NIAID, NIH, Rockville, MD 20852, USA
| | - John F Andersen
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7LG, UK
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIAID, NIH, MD 20892-8132, USA.
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5
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Hughes E, Wallender E, Mohamed Ali A, Jagannathan P, Savic RM. Malaria PK/PD and the Role Pharmacometrics Can Play in the Global Health Arena: Malaria Treatment Regimens for Vulnerable Populations. Clin Pharmacol Ther 2021; 110:926-940. [PMID: 33763871 PMCID: PMC8518425 DOI: 10.1002/cpt.2238] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/05/2021] [Indexed: 12/23/2022]
Abstract
Malaria is an infectious disease which disproportionately effects children and pregnant women. These vulnerable populations are often excluded from clinical trials resulting in one‐size‐fits‐all treatment regimens based on those established for a nonpregnant adult population. Pharmacokinetic/pharmacodynamic (PK/PD) models can be used to optimize dose selection as they define the drug exposure‐response relationship. Additionally, these models are able to identify patient characteristics that cause alterations in the expected PK/PD profiles and through simulations can recommend changes to dosing which compensate for the differences. In this review, we examine how PK/PD models have been applied to optimize antimalarial dosing recommendations for young children, including those who are malnourished, pregnant women, and individuals receiving concomitant therapies such as those for HIV treatment. The malaria field has had great success in utilizing PK/PD models as a foundation to update treatment guidelines and propose the next generation of dosing regimens to investigate in clinical trials. We propose how the malaria field can continue to use modeling to improve therapies by further integrating PK data into clinical studies and including data on drug resistance and host immunity in PK/PD models. Finally, we suggest that other disease areas can achieve similar success in applying pharmacometrics to improve outcomes by implementing three key principals.
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Affiliation(s)
- Emma Hughes
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | - Erika Wallender
- Department of Clinical Pharmacy, University of California San Francisco, San Francisco, California, USA
| | - Ali Mohamed Ali
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | | | - Radojka M Savic
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
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6
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Challenger JD, Gonçalves BP, Bradley J, Bruxvoort K, Tiono AB, Drakeley C, Bousema T, Ghani AC, Okell LC. How delayed and non-adherent treatment contribute to onward transmission of malaria: a modelling study. BMJ Glob Health 2019; 4:e001856. [PMID: 31908862 PMCID: PMC6936434 DOI: 10.1136/bmjgh-2019-001856] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 12/31/2022] Open
Abstract
Introduction Artemether-lumefantrine (AL) is the most widely-recommended treatment for uncomplicated Plasmodium falciparum malaria. Its efficacy has been extensively assessed in clinical trials. In routine healthcare settings, however, its effectiveness can be diminished by delayed access to treatment and poor adherence. As well as affecting clinical outcomes, these factors can lead to increased transmission, which is the focus of this study. Methods We extend a within-host model of P. falciparum to include gametocytes, the parasite forms responsible for onward transmission. The model includes a pharmacokinetic–pharmacodynamic model of AL, calibrated against both immature and mature gametocytes using individual-level patient data, to estimate the impact that delayed access and imperfect adherence to treatment can have on onward transmission of the parasite to mosquitoes. Results Using survey data from seven African countries to determine the time taken to acquire antimalarials following fever increased our estimates of mean total infectivity of a malaria episode by up to 1.5-fold, compared with patients treated after 24 hours. Realistic adherence behaviour, based on data from a monitored cohort in Tanzania, increased the contribution to transmission by 2.2 to 2.4-fold, compared with a perfectly-adherent cohort. This was driven largely by increased rates of treatment failure leading to chronic infection, rather than prolonged gametocytaemia in patients who have slower, but still successful, clearance of parasites after imperfect adherence to treatment. Our model estimated that the mean infectivity of untreated infections was 29–51 times higher than that of treated infections (assuming perfect drug adherence), underlining the importance of improving treatment coverage. Conclusion Using mathematical modelling, we quantify how delayed treatment and non-adherent treatment can increase transmission compared with prompt effective treatment. We also highlight that transmission from the large proportion of infections which never receive treatment is substantially higher than those treated.
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Affiliation(s)
- Joseph D Challenger
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Katia Bruxvoort
- Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA.,Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alfred B Tiono
- Public Health Department, Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Radboud Institute of Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Lucy C Okell
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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7
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Chotsiri P, Denoeud‐Ndam L, Baudin E, Guindo O, Diawara H, Attaher O, Smit M, Guerin PJ, Doumbo OK, Wiesner L, Barnes KI, Hoglund RM, Dicko A, Etard J, Tarning J. Severe Acute Malnutrition Results in Lower Lumefantrine Exposure in Children Treated With Artemether-Lumefantrine for Uncomplicated Malaria. Clin Pharmacol Ther 2019; 106:1299-1309. [PMID: 31152555 PMCID: PMC6896236 DOI: 10.1002/cpt.1531] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 05/08/2019] [Indexed: 01/28/2023]
Abstract
Severe acute malnutrition (SAM) has been reported to be associated with increased malaria morbidity in Sub-Saharan African children and may affect the pharmacology of antimalarial drugs. This population pharmacokinetic (PK)-pharmacodynamic study included 131 SAM and 266 non-SAM children administered artemether-lumefantrine twice daily for 3 days. Lumefantrine capillary plasma concentrations were adequately described by two transit-absorption compartments followed by two distribution compartments. Allometrically scaled body weight and an enzymatic maturation effect were included in the PK model. Mid-upper arm circumference was associated with decreased absorption of lumefantrine (25.4% decreased absorption per 1 cm reduction). Risk of recurrent malaria episodes (i.e., reinfection) were characterized by an interval-censored time-to-event model with a sigmoid maximum-effect model describing the effect of lumefantrine. SAM children were at risk of underexposure to lumefantrine and an increased risk of malaria reinfection compared with well-nourished children. Research on optimized regimens should be considered for malaria treatment in malnourished children.
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Affiliation(s)
- Palang Chotsiri
- Mahidol‐Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
| | | | | | | | - Halimatou Diawara
- Malaria Research and Training CentreFaculty of Medicine Pharmacy and DentistryUniversity of BamakoBamakoMali
| | - Oumar Attaher
- Malaria Research and Training CentreFaculty of Medicine Pharmacy and DentistryUniversity of BamakoBamakoMali
| | - Michiel Smit
- Division of Clinical PharmacologyDepartment of MedicineUniversity of Cape TownCape TownSouth Africa
| | - Philippe J. Guerin
- WorldWide Antimalarial Resistance Network (WWARN)OxfordUK
- Centre for Tropical Medicine and Global HealthNuffield Department of MedicineOxford UniversityOxfordUK
| | - Ogobara K. Doumbo
- Malaria Research and Training CenterFaculté de Médecine et d'Odonto‐stomatologie et Faculté de PharmacieUniversité des Sciences Techniques et Technologies de BamakoBamakoMali
| | - Lubbe Wiesner
- Division of Clinical PharmacologyDepartment of MedicineUniversity of Cape TownCape TownSouth Africa
| | - Karen I. Barnes
- Division of Clinical PharmacologyDepartment of MedicineUniversity of Cape TownCape TownSouth Africa
- WorldWide Antimalarial Resistance Network (WWARN)OxfordUK
| | - Richard M. Hoglund
- Mahidol‐Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global HealthNuffield Department of MedicineOxford UniversityOxfordUK
| | - Alassane Dicko
- Malaria Research and Training CenterFaculté de Médecine et d'Odonto‐stomatologie et Faculté de PharmacieUniversité des Sciences Techniques et Technologies de BamakoBamakoMali
| | - Jean‐Francois Etard
- EpicentreParisFrance
- TransVIHMI UMI 233Institut de recherche pour le développement (IRD)Inserm U 1175Montpellier 1 UniversityMontpellierFrance
| | - Joel Tarning
- Mahidol‐Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
- WorldWide Antimalarial Resistance Network (WWARN)OxfordUK
- Centre for Tropical Medicine and Global HealthNuffield Department of MedicineOxford UniversityOxfordUK
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8
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Guidi M, Mercier T, Aouri M, Decosterd LA, Csajka C, Ogutu B, Carn G, Kiechel JR. Population pharmacokinetics and pharmacodynamics of the artesunate-mefloquine fixed dose combination for the treatment of uncomplicated falciparum malaria in African children. Malar J 2019; 18:139. [PMID: 30999915 PMCID: PMC6471806 DOI: 10.1186/s12936-019-2754-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 03/29/2019] [Indexed: 12/02/2022] Open
Abstract
Background The World Health Organization (WHO) recommends combinations of an artemisinin derivative plus an anti-malarial drug of longer half-life as treatment options for uncomplicated Plasmodium falciparum infections. In Africa, artesunate–mefloquine (ASMQ) is an infrequently used artemisinin-based combination therapy (ACT) because of perceived poor tolerance to mefloquine. However, the WHO has recommended reconsideration of the use of ASMQ in Africa. In this large clinical study, the pharmacokinetics (PK) of a fixed dose combination of ASMQ was investigated in an African paediatric population to support dosing recommendations used in Southeast Asia and South America. Methods Among the 472 paediatric patients aged 6–59 months from six African centres included in the large clinical trial, a subset of 50 Kenyan children underwent intensive sampling to develop AS, its metabolite dihydroartemisinin (DHA) and MQ PK models. The final MQ PK model was validated using sparse data collected in the remaining participants (NONMEM®). The doses were one or two tablets containing 25/55 mg AS/MQ administered once a day for 3 days according to patients’ age. A sensitive LC–MS/MS method was used to quantify AS, DHA and MQ concentrations in plasma. An attempt was made to investigate the relationship between the absence/presence of malaria recrudescence and MQ area under the curve (AUC) using logistic regression. Results AS/DHA concentration–time profiles were best described using a one-compartment model for both compounds with irreversible AS conversion into DHA. AS/DHA PK were characterized by a significant degree of variability. Body weight affected DHA PK parameters. MQ PK was characterized by a two-compartment model and a large degree of variability. Allometric scaling of MQ clearances and volumes of distribution was used to depict the relationship between MQ PK and body weight. No association was found between the model predicted AUC and appearance of recrudescence. Conclusions The population pharmacokinetic models developed for both AS/DHA and MQ showed a large variability in drug exposure in the investigated African paediatric population. The largest contributor to this variability was body weight, which is accommodated for by the ASMQ fixed dose combination (FDC) dosing recommendation. Besides body weight considerations, there is no indication that the dosage should be modified in children with malaria compared to adults. Trial registration Pan African Clinical Trials Registry PACTR201202000278282 registration date 2011/02/16 Electronic supplementary material The online version of this article (10.1186/s12936-019-2754-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Monia Guidi
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland.,Laboratory and Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Thomas Mercier
- Laboratory and Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Manel Aouri
- Laboratory and Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Laurent A Decosterd
- Laboratory and Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Chantal Csajka
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland.,Laboratory and Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | | | - Gwénaëlle Carn
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
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9
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Hoglund RM, Ruengweerayut R, Na-Bangchang K. Population pharmacokinetics of mefloquine given as a 3-day artesunate-mefloquine in patients with acute uncomplicated Plasmodium falciparum malaria in a multidrug-resistant area along the Thai-Myanmar border. Malar J 2018; 17:322. [PMID: 30176888 PMCID: PMC6122721 DOI: 10.1186/s12936-018-2466-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 08/27/2018] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Low mefloquine exposure has been shown to contribute to treatment failure in patients with uncomplicated falciparum malaria following a 3-day artesunate-mefloquine combination. The present study aimed to develop a population pharmacokinetic model for mefloquine based on whole blood concentration-time profiles of this target population for further dose optimization. METHODS A total of 129 Burmese patients aged above 15 years who presented with typical symptoms of malaria and had a blood smear positive for Plasmodium falciparum were included in the study. All were treated with the standard 3-day combination regimen of artesunate and mefloquine consisting of mefloquine for 2 days and artesunate for 3 days. Blood samples were collected before and at different time points after drug administration from different sub-groups of patients. Mefloquine concentrations were quantified in whole blood using high-performance liquid chromatography. A non-linear mixed-effect modelling approach was applied for population pharmacokinetic analysis using the NONMEM v7.3 software. Covariates investigated (body weight, gender, admission parasitaemia, and molecular markers of mefloquine resistance) were investigated in a step-wise manner using the SCM functionality in Perl-Speaks-NONMEM. RESULTS Population pharmacokinetic analysis of mefloquine was performed in all patients with a total of 653 samples. Whole blood mefloquine concentration-time profiles were described by a two-compartment disposition model. Of the covariates investigated, none was found to have a significant impact on the pharmacokinetics of mefloquine. Significant differences in maximum concentration (Cmax) and elimination half-life (t1/2) were found in patients who had treatment failure (36 cases) compared to patients with successful treatment (107 cases). CONCLUSION The study successfully describes the pharmacokinetics of mefloquine following a 2-day treatment of mefloquine as a part of a 3-day artesunate-mefloquine in patients with uncomplicated falciparum malaria from Thailand. A model has been developed which adequately describes the pharmacokinetics of mefloquine. More extensive clinical studies including both adults and children are needed to fully characterize the pharmacokinetics of mefloquine.
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Affiliation(s)
- Richard M Hoglund
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Kesara Na-Bangchang
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and Cholangiocarcinoma, Thammasat University, Pathumtanee, Thailand.
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10
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Gallay J, Mosha D, Lutahakana E, Mazuguni F, Zuakulu M, Decosterd LA, Genton B, Pothin E. Appropriateness of malaria diagnosis and treatment for fever episodes according to patient history and anti-malarial blood measurement: a cross-sectional survey from Tanzania. Malar J 2018; 17:209. [PMID: 29784001 PMCID: PMC5963060 DOI: 10.1186/s12936-018-2357-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 05/14/2018] [Indexed: 12/28/2022] Open
Abstract
Background Monitoring the impact of case management strategies at large scale is essential to evaluate the public health benefit they confer. The use of methodologies relying on objective and standardized endpoints, such as drug levels in the blood, should be encouraged. Population drug use, diagnosis and treatment appropriateness in case of fever according to patient history and anti-malarials blood concentration was evaluated. Methods A cross-sectional survey took place between May and August 2015 in three regions of Tanzania with different levels of malaria endemicity. Interviews were conducted and blood samples were collected by dried blood spots through household surveys for further anti-malarial measurements. Appropriate testing when individuals attended care was defined as a patient with history of fever being tested for malaria and appropriate treatment as (i) having anti-malarial in the blood if the test result was positive (ii) having anti-malarial in the blood if the person was not tested, and (iii) no anti-malarial in the blood when the test result was negative. Results Amongst 6391 participants included in the anti-malarial analysis, 20.8% (1330/6391) had anti-malarial drug detected in the blood. Only 28.0% (372/1330) of the individuals with anti-malarials in their blood reported the use of anti-malarials within the previous month. Amongst all participants, 16.0% (1021/6391) reported having had a fever in the previous 2 weeks and 37.5% of them (383/1021) had detectable levels of anti-malarials in the blood. Of the individuals who sought care in health facilities, 69.4% (172/248) were tested and 52.0% (129/248) appropriately treated. When other providers were sought, 6% (23/382) of the persons were appropriately tested and 44.2% (169/382) appropriately treated. Overall, the proportion of individuals treated was larger than that being tested [47.3% (298/630) treated, 31.0% (195/630) tested]. Conclusion This study showed high prevalence of circulating anti-malarial drug in the sampled population. Efforts should be made to increase rapid diagnostic tests use at all levels of health care and improve compliance to test result in order to target febrile patients that are sick with malaria and reduce drug pressure. Objective drug measurements collected at community level represent a reliable tool to evaluate overall impact of case management strategies on population drug pressure.
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Affiliation(s)
- Joanna Gallay
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box 4002, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Service and Laboratory of Clinical Pharmacology, University Hospital, Lausanne, Switzerland.
| | | | | | | | | | | | - Blaise Genton
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box 4002, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Division of Infectious Diseases and Department of Community Health, University Hospital, Lausanne, Switzerland
| | - Emilie Pothin
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box 4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
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11
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Assessing the impact of imperfect adherence to artemether-lumefantrine on malaria treatment outcomes using within-host modelling. Nat Commun 2017; 8:1373. [PMID: 29123086 PMCID: PMC5680187 DOI: 10.1038/s41467-017-01352-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 09/12/2017] [Indexed: 12/31/2022] Open
Abstract
Artemether-lumefantrine (AL) is the most widely-recommended treatment for uncomplicated Plasmodium falciparum malaria worldwide. Its safety and efficacy have been extensively demonstrated in clinical trials; however, its performance in routine health care settings, where adherence to drug treatment is unsupervised and therefore may be suboptimal, is less well characterised. Here we develop a within-host modelling framework for estimating the effects of sub-optimal adherence to AL treatment on clinical outcomes in malaria patients. Our model incorporates the data on the human immune response to the parasite, and AL's pharmacokinetic and pharmacodynamic properties. Utilising individual-level data of adherence to AL in 482 Tanzanian patients as input for our model predicted higher rates of treatment failure than were obtained when adherence was optimal (9% compared to 4%). Our model estimates that the impact of imperfect adherence was worst in children, highlighting the importance of advice to caregivers.
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12
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Sugiarto SR, Davis TME, Salman S. Pharmacokinetic considerations for use of artemisinin-based combination therapies against falciparum malaria in different ethnic populations. Expert Opin Drug Metab Toxicol 2017; 13:1115-1133. [PMID: 29027504 DOI: 10.1080/17425255.2017.1391212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Artemisinin-based combination therapy (ACT) is used extensively as first-line treatment for uncomplicated falciparum malaria. There has been no rigorous assessment of the potential for racial/ethnic differences in the pharmacokinetic properties of ACTs that might influence their efficacy. Areas covered: A comprehensive literature search was performed that identified 72 publications in which the geographical origin of the patients could be ascertained and the key pharmacokinetic parameters maximum drug concentration (Cmax), area under the plasma concentration-time curve (AUC) and elimination half-life (t½β) were available for one or more of the five WHO-recommended ACTs (artemether-lumefantrine, artesunate-amodiaquine, artesunate-mefloquine, dihydroartemisinin-piperaquine and artesunate-sulfadoxine-pyrimethamine). Comparisons of each of the three pharmacokinetic parameters of interest were made by drug (artemisinin derivative and long half-life partner), race/ethnicity (African, Asian, Caucasian, Melanesian, South American) and patient categories based on age and pregnancy status. Expert opinion: The review identified no evidence of a clinically significant influence of race/ethnicity on the pharmacokinetic properties of the nine component drugs in the five ACTs currently recommended by WHO for first-line treatment of uncomplicated falciparum malaria. This provides reassurance for health workers in malaria-endemic regions that ACTs can be given in recommended doses with the expectation of adequate blood concentrations regardless of race/ethnicity.
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Affiliation(s)
- Sri Riyati Sugiarto
- a Medical School , University of Western Australia, Fremantle Hospital , Fremantle , Australia
| | - Timothy M E Davis
- a Medical School , University of Western Australia, Fremantle Hospital , Fremantle , Australia
| | - Sam Salman
- a Medical School , University of Western Australia, Fremantle Hospital , Fremantle , Australia
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13
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Chotsiri P, Wattanakul T, Hoglund RM, Hanboonkunupakarn B, Pukrittayakamee S, Blessborn D, Jittamala P, White NJ, Day NPJ, Tarning J. Population pharmacokinetics and electrocardiographic effects of dihydroartemisinin-piperaquine in healthy volunteers. Br J Clin Pharmacol 2017; 83:2752-2766. [PMID: 28695570 PMCID: PMC5698590 DOI: 10.1111/bcp.13372] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 06/21/2017] [Accepted: 06/30/2017] [Indexed: 12/21/2022] Open
Abstract
Aims The aims of the present study were to evaluate the pharmacokinetic properties of dihydroartemisinin (DHA) and piperaquine, potential drug–drug interactions with concomitant primaquine treatment, and piperaquine effects on the electrocardiogram in healthy volunteers. Methods The population pharmacokinetic properties of DHA and piperaquine were assessed in 16 healthy Thai adults using an open‐label, randomized, crossover study. Drug concentration–time data and electrocardiographic measurements were evaluated with nonlinear mixed‐effects modelling. Results The developed models described DHA and piperaquine population pharmacokinetics accurately. Concomitant treatment with primaquine did not affect the pharmacokinetic properties of DHA or piperaquine. A linear pharmacokinetic–pharmacodynamic model described satisfactorily the relationship between the individually corrected QT intervals and piperaquine concentrations; the population mean QT interval increased by 4.17 ms per 100 ng ml–1 increase in piperaquine plasma concentration. Simulations from the final model showed that monthly and bimonthly mass drug administration in healthy subjects would result in median maximum QT interval prolongations of 18.9 ms and 16.8 ms, respectively, and would be very unlikely to result in prolongation of more than 50 ms. A single low dose of primaquine can be added safely to the existing DHA–piperaquine treatment in areas of multiresistant Plasmodium falciparum malaria. Conclusions Pharmacokinetic–pharmacodynamic modelling and simulation in healthy adult volunteers suggested that therapeutic doses of DHA–piperaquine in the prevention or treatment of P. falciparum malaria are unlikely to be associated with dangerous QT prolongation.
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Affiliation(s)
- Palang Chotsiri
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thanaporn Wattanakul
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Richard M Hoglund
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | | | | | - Daniel Blessborn
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | | | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
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14
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Tchaparian E, Sambol NC, Arinaitwe E, McCormack SA, Bigira V, Wanzira H, Muhindo M, Creek DJ, Sukumar N, Blessborn D, Tappero JW, Kakuru A, Bergqvist Y, Aweeka FT, Parikh S. Population Pharmacokinetics and Pharmacodynamics of Lumefantrine in Young Ugandan Children Treated With Artemether-Lumefantrine for Uncomplicated Malaria. J Infect Dis 2016; 214:1243-51. [PMID: 27471317 PMCID: PMC5034953 DOI: 10.1093/infdis/jiw338] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 07/23/2016] [Indexed: 12/21/2022] Open
Abstract
Background. The pharmacokinetics and pharmacodynamics of lumefantrine, a component of the most widely used treatment for malaria, artemether-lumefantrine, has not been adequately characterized in young children. Methods. Capillary whole-blood lumefantrine concentration and treatment outcomes were determined in 105 Ugandan children, ages 6 months to 2 years, who were treated for 249 episodes of Plasmodium falciparum malaria with artemether-lumefantrine. Results. Population pharmacokinetics for lumefantrine used a 2-compartment open model with first-order absorption. Age had a significant positive correlation with bioavailability in a model that included allometric scaling. Children not receiving trimethoprim-sulfamethoxazole with capillary whole blood concentrations <200 ng/mL had a 3-fold higher hazard of 28-day recurrent parasitemia, compared with those with concentrations >200 ng/mL (P = .0007). However, for children receiving trimethoprim-sulfamethoxazole, the risk of recurrent parasitemia did not differ significantly on the basis of this threshold. Day 3 concentrations were a stronger predictor of 28-day recurrence than day 7 concentrations. Conclusions. We demonstrate that age, in addition to weight, is a determinant of lumefantrine exposure, and in the absence of trimethoprim-sulfamethoxazole, lumefantrine exposure is a determinant of recurrent parasitemia. Exposure levels in children aged 6 months to 2 years was generally lower than levels published for older children and adults. Further refinement of artemether-lumefantrine dosing to improve exposure in infants and very young children may be warranted.
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Affiliation(s)
- Eskouhie Tchaparian
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco
| | - Nancy C Sambol
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco
| | | | - Shelley A McCormack
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco
| | - Victor Bigira
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Mary Muhindo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Darren J Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
| | - Nitin Sukumar
- Yale School of Public Health, New Haven, Connecticut
| | | | - Jordan W Tappero
- Centers for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Abel Kakuru
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Sunil Parikh
- Yale School of Public Health, New Haven, Connecticut
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15
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Mutagonda RF, Kamuhabwa AAR, Minzi OMS, Massawe SN, Maganda BA, Aklillu E. Malaria prevalence, severity and treatment outcome in relation to day 7 lumefantrine plasma concentration in pregnant women. Malar J 2016; 15:278. [PMID: 27177586 PMCID: PMC4866074 DOI: 10.1186/s12936-016-1327-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/04/2016] [Indexed: 12/28/2022] Open
Abstract
Background Day 7 plasma concentrations of lumefantrine (LF) can serve as a marker to predict malaria treatment outcome in different study populations. Two main cut-off points (175 and 280 ng/ml) are used to indicate plasma concentrations of LF, below which treatment failure is anticipated. However, there is limited data on the cumulative risk of recurrent parasitaemia (RP) in relation to day 7 LF plasma concentrations in pregnant women. This study describes the prevalence, severity, factors influencing treatment outcome of malaria in pregnancy and day 7 LF plasma concentration therapeutic cut-off points that predicts treatment outcome in pregnant women. Methods This was a one-arm prospective cohort study whereby 89 pregnant women with uncomplicated Plasmodium falciparum malaria receiving artemether-lumefantrine (ALu) participated in pharmacokinetics and pharmacodynamics study. Blood samples were collected on days 0, 2, 7, 14, 21 and 28 for malaria parasite quantification. LF plasma concentrations were determined on day 7. The primary outcome measure was an adequate clinical and parasitological response (ACPR) after treatment with ALu. Results The prevalence of malaria in pregnant women was 8.1 % (95 % CI 6.85–9.35) of whom 3.4 % (95 % CI 1.49–8.51) had severe malaria. The overall PCR-uncorrected treatment failure rate was 11.7 % (95 % CI 0.54–13.46 %). Low baseline hemoglobin (<10 g/dl) and day 7 LF concentration <600 ng/ml were significant predictors of RP. The median day 7 LF concentration was significantly lower in pregnant women with RP (270 ng/ml) than those with ACPR (705 ng/ml) (p = 0.016). The relative risk of RP was 4.8 folds higher (p = 0.034) when cut-off of <280 ng/ml was compared to ≥280 ng/ml and 7.8-folds higher (p = 0.022) when cut-off of <600 ng/ml was compared to ≥600 ng/ml. The cut-off value of 175 ng/ml was not associated with the risk of RP (p = 0.399). Conclusions Pregnant women with day 7 LF concentration <600 ng/ml are at high risk of RP than those with ≥600 ng/ml. To achieve effective therapeutic outcome, higher day 7 venous plasma LF concentration ≥600 ng/ml is required for pregnant patients than the previously suggested cut-off value of 175 or 280 ng/ml for non-pregnant adult patients.
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Affiliation(s)
- Ritah F Mutagonda
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. BOX 65013, Dar es Salaam, Tanzania.
| | - Appolinary A R Kamuhabwa
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. BOX 65013, Dar es Salaam, Tanzania
| | - Omary M S Minzi
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. BOX 65013, Dar es Salaam, Tanzania
| | - Siriel N Massawe
- Department of Obstetrics and Gynaecology, School of Medicine, Muhimbili University of Allied Sciences, P.O. BOX 65013, Dar es Salaam, Tanzania
| | - Betty A Maganda
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. BOX 65013, Dar es Salaam, Tanzania
| | - Eleni Aklillu
- Department of Laboratory of Medicine, Division of Clinical Pharmacology, Karolinska Institutet, 141 86, Stockholm, Sweden
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16
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Yang A, Zang M, Liu H, Fan P, Xing J. Metabolite identification of the antimalarial piperaquinein vivousing liquid chromatography-high-resolution mass spectrometry in combination with multiple data-mining tools in tandem. Biomed Chromatogr 2016; 30:1324-30. [DOI: 10.1002/bmc.3689] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 12/22/2015] [Accepted: 01/24/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Aijuan Yang
- School of Pharmaceutical Sciences; Shandong University; Jinan China
| | - Meitong Zang
- School of Pharmaceutical Sciences; Shandong University; Jinan China
| | - Huixiang Liu
- School of Pharmaceutical Sciences; Shandong University; Jinan China
| | - Peihong Fan
- School of Pharmaceutical Sciences; Shandong University; Jinan China
| | - Jie Xing
- School of Pharmaceutical Sciences; Shandong University; Jinan China
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17
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Designing a Pediatric Study for an Antimalarial Drug by Using Information from Adults. Antimicrob Agents Chemother 2015; 60:1481-91. [PMID: 26711749 DOI: 10.1128/aac.01125-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 12/08/2015] [Indexed: 12/19/2022] Open
Abstract
The objectives of this study were to design a pharmacokinetic (PK) study by using information about adults and evaluate the robustness of the recommended design through a case study of mefloquine. PK data about adults and children were available from two different randomized studies of the treatment of malaria with the same artesunate-mefloquine combination regimen. A recommended design for pediatric studies of mefloquine was optimized on the basis of an extrapolated model built from adult data through the following approach. (i) An adult PK model was built, and parameters were estimated by using the stochastic approximation expectation-maximization algorithm. (ii) Pediatric PK parameters were then obtained by adding allometry and maturation to the adult model. (iii) A D-optimal design for children was obtained with PFIM by assuming the extrapolated design. Finally, the robustness of the recommended design was evaluated in terms of the relative bias and relative standard errors (RSE) of the parameters in a simulation study with four different models and was compared to the empirical design used for the pediatric study. Combining PK modeling, extrapolation, and design optimization led to a design for children with five sampling times. PK parameters were well estimated by this design with few RSE. Although the extrapolated model did not predict the observed mefloquine concentrations in children very accurately, it allowed precise and unbiased estimates across various model assumptions, contrary to the empirical design. Using information from adult studies combined with allometry and maturation can help provide robust designs for pediatric studies.
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18
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Altering Antimalarial Drug Regimens May Dramatically Enhance and Restore Drug Effectiveness. Antimicrob Agents Chemother 2015; 59:6419-27. [PMID: 26239993 DOI: 10.1128/aac.00482-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 07/22/2015] [Indexed: 01/16/2023] Open
Abstract
There is considerable concern that malaria parasites are starting to evolve resistance to the current generation of antimalarial drugs, the artemisinin-based combination therapies (ACTs). We use pharmacological modeling to investigate changes in ACT effectiveness likely to occur if current regimens are extended from 3 to 5 days or, alternatively, given twice daily over 3 days. We show that the pharmacology of artemisinins allows both regimen changes to substantially increase the artemisinin killing rate. Malaria patients rarely contain more than 10(12) parasites, while the standard dosing regimens allow approximately 1 in 10(10) parasites to survive artemisinin treatment. Parasite survival falls dramatically, to around 1 in 10(17) parasites if the dose is extended or split; theoretically, this increase in drug killing appears to be more than sufficient to restore failing ACT efficacy. One of the most widely used dosing regimens, artemether-lumefantrine, already successfully employs a twice-daily dosing regimen, and we argue that twice-daily dosing should be incorporated into all ACT regimen design considerations as a simple and effective way of ensuring the continued long-term effectiveness of ACTs.
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19
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Kay K, Hastings IM. Measuring windows of selection for anti-malarial drug treatments. Malar J 2015; 14:292. [PMID: 26228915 PMCID: PMC4521485 DOI: 10.1186/s12936-015-0810-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/15/2015] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The long half-lives of malaria 'partner' drugs are a potent force selecting for drug resistance. Clinical trials can quantify this effect by estimating a window of selection (WoS), defined as the amount of time post-treatment when drug levels are sufficiently high that resistant parasites can re-establish an infection while preventing drug-sensitive parasites from establishing viable infections. METHODS The ability of clinical data to accurately estimate the true WoS was investigated using standard pharmacokinetic-pharmacodynamic models for three widely used malaria drugs: artemether-lumefantrine (AR-LF), artesunate-mefloquine (AS-MQ) and dihydroartemisinin-piperaquine (DHA-PPQ). Estimates of the clinical WoS either (1) ignored all new infections occurring after the 63-day follow-up period, as is currently done in clinical trials, or, (2) recognized that all individuals would eventually be re-infected and arbitrarily assigned them a new infection day. RESULTS The results suggest current methods of estimating the clinical WoS underestimate the true WoS by as much as 9 days for AR-LF, 33 days for AS-MQ and 7 days for DHA-PPQ. The new method of estimating clinical WoS (i.e., retaining all individuals in the analysis) was significantly better at estimating the true WoS for AR-LF and AS-MQ. CONCLUSIONS Previous studies, based on clinically observed WoS, have probably underestimated the 'true' WoS and hence the role of drugs with long half-lives in driving resistance. This has important policy implications: high levels of drug use are inevitable in mass drug administration programmes and intermittent preventative treatment programmes and the analysis herein suggests these policies will be far more potent drivers of resistance than previously thought.
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Affiliation(s)
- Katherine Kay
- Parasitology Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Ian M Hastings
- Parasitology Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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20
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Sambol NC, Yan L, Creek DJ, McCormack SA, Arinaitwe E, Bigira V, Wanzira H, Kakuru A, Tappero JW, Lindegardh N, Tarning J, Nosten F, Aweeka FT, Parikh S. Population Pharmacokinetics of Piperaquine in Young Ugandan Children Treated With Dihydroartemisinin-Piperaquine for Uncomplicated Malaria. Clin Pharmacol Ther 2015; 98:87-95. [PMID: 25732044 PMCID: PMC5088713 DOI: 10.1002/cpt.104] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 02/20/2015] [Accepted: 02/24/2015] [Indexed: 01/09/2023]
Abstract
This prospective trial investigated the population pharmacokinetics of piperaquine given with dihydroartemisinin to treat uncomplicated malaria in 107 Ugandan children 6 months to 2 years old, an age group previously unstudied. Current weight-based dosing does not adequately address physiological changes in early childhood. Patients were administered standard 3-day oral doses and provided 1,282 capillary plasma concentrations from 218 malaria episodes. Less than 30% of treatments achieved 57 ng/mL on day 7. A three-compartment model with first-order absorption described the data well. Age had a statistically significant effect (P < 0.005) on clearance/bioavailability in a model that accounts for allometric scaling. Simulations demonstrated that higher doses in all children, but especially in those with lower weight for age, are required for adequate piperaquine exposure, although safety and tolerance will need to be established. These findings support other evidence that both weight- and age-specific guidelines for piperaquine dosing in children are urgently needed.
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Affiliation(s)
- Nancy C. Sambol
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
- Department of Clinical Pharmacy, University of California San Francisco, San Francisco, CA, USA
| | - Li Yan
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Darren J. Creek
- Department of Clinical Pharmacy, University of California San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Shelley A. McCormack
- Department of Clinical Pharmacy, University of California San Francisco, San Francisco, CA, USA
| | | | - Victor Bigira
- Makerere University School of Medicine, Kampala, Uganda
| | | | - Abel Kakuru
- Makerere University School of Medicine, Kampala, Uganda
| | - Jordan W. Tappero
- Centers for Global Health, Centers for Disease Control and Prevention (CDC), Atlanta, GA
| | - Niklas Lindegardh
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Francois Nosten
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Francesca T. Aweeka
- Department of Clinical Pharmacy, University of California San Francisco, San Francisco, CA, USA
| | - Sunil Parikh
- Yale School of Public Health and Medicine, New Haven, CT, USA
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21
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Kumar S, Kumari R, Pandey R. New insight-guided approaches to detect, cure, prevent and eliminate malaria. PROTOPLASMA 2015; 252:717-753. [PMID: 25323622 DOI: 10.1007/s00709-014-0697-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 09/01/2014] [Indexed: 06/04/2023]
Abstract
New challenges posed by the development of resistance against artemisinin-based combination therapies (ACTs) as well as previous first-line therapies, and the continuing absence of vaccine, have given impetus to research in all areas of malaria control. This review portrays the ongoing progress in several directions of malaria research. The variants of RTS,S and apical membrane antigen 1 (AMA1) are being developed and test adapted as multicomponent and multistage malaria control vaccines, while many other vaccine candidates and methodologies to produce antigens are under experimentation. To track and prevent the spread of artemisinin resistance from Southeast Asia to other parts of the world, rolling circle-enhanced enzyme activity detection (REEAD), a time- and cost-effective malaria diagnosis in field conditions, and a DNA marker associated with artemisinin resistance have become available. Novel mosquito repellents and mosquito trapping and killing techniques much more effective than the prevalent ones are undergoing field testing. Mosquito lines stably infected with their symbiotic wild-type or genetically engineered bacteria that kill sympatric malaria parasites are being constructed and field tested for stopping malaria transmission. A complementary approach being pursued is the addition of ivermectin-like drug molecules to ACTs to cure malaria and kill mosquitoes. Experiments are in progress to eradicate malaria mosquito by making it genetically male sterile. High-throughput screening procedures are being developed and used to discover molecules that possess long in vivo half life and are active against liver and blood stages for the fast cure of malaria symptoms caused by simple or relapsing and drug-sensitive and drug-resistant types of varied malaria parasites, can stop gametocytogenesis and sporogony and could be given in one dose. Target-based antimalarial drug designing has begun. Some of the putative next-generation antimalarials that possess in their scaffold structure several of the desired properties of malaria cure and control are exemplified by OZ439, NITD609, ELQ300 and tafenoquine that are already undergoing clinical trials, and decoquinate, usnic acid, torin-2, ferroquine, WEHI-916, MMV396749 and benzothiophene-type N-myristoyltransferase (NMT) inhibitors, which are candidates for future clinical usage. Among these, NITD609, ELQ300, decoquinate, usnic acid, torin-2 and NMT inhibitors not only cure simple malaria and are prophylactic against simple malaria, but they also cure relapsing malaria.
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Affiliation(s)
- Sushil Kumar
- SKA Institution for Research, Education and Development (SKAIRED), 4/11 SarvPriya Vihar, New Delhi, 110016, India,
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22
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Gerardin J, Eckhoff P, Wenger EA. Mass campaigns with antimalarial drugs: a modelling comparison of artemether-lumefantrine and DHA-piperaquine with and without primaquine as tools for malaria control and elimination. BMC Infect Dis 2015; 15:144. [PMID: 25887935 PMCID: PMC4376519 DOI: 10.1186/s12879-015-0887-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/12/2015] [Indexed: 12/31/2022] Open
Abstract
Background Antimalarial drugs are a powerful tool for malaria control and elimination. Artemisinin-based combination therapies (ACTs) can reduce transmission when widely distributed in a campaign setting. Modelling mass antimalarial campaigns can elucidate how to most effectively deploy drug-based interventions and quantitatively compare the effects of cure, prophylaxis, and transmission-blocking in suppressing parasite prevalence. Methods A previously established agent-based model that includes innate and adaptive immunity was used to simulate malaria infections and transmission. Pharmacokinetics of artemether, lumefantrine, dihydroartemisinin, piperaquine, and primaquine were modelled with a double-exponential distribution-elimination model including weight-dependent parameters and age-dependent dosing. Drug killing of asexual parasites and gametocytes was calibrated to clinical data. Mass distribution of ACTs and primaquine was simulated with seasonal mosquito dynamics at a range of transmission intensities. Results A single mass campaign with antimalarial drugs is insufficient to permanently reduce malaria prevalence when transmission is high. Current diagnostics are insufficiently sensitive to accurately identify asymptomatic infections, and mass-screen-and-treat campaigns are much less efficacious than mass drug administrations. Improving campaign coverage leads to decreased prevalence one month after the end of the campaign, while increasing compliance lengthens the duration of protection against reinfection. Use of a long-lasting prophylactic as part of a mass drug administration regimen confers the most benefit under conditions of high transmission and moderately high coverage. Addition of primaquine can reduce prevalence but exerts its largest effect when coupled with a long-lasting prophylactic. Conclusions Mass administration of antimalarial drugs can be a powerful tool to reduce prevalence for a few months post-campaign. A slow-decaying prophylactic administered with a parasite-clearing drug offers strong protection against reinfection, especially in highly endemic areas. Transmission-blocking drugs have only limited effects unless administered with a prophylactic under very high coverage. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-0887-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jaline Gerardin
- Institute for Disease Modeling, Intellectual Ventures, 1555 132nd Ave NE, Bellevue, WA, 98005, USA.
| | - Philip Eckhoff
- Institute for Disease Modeling, Intellectual Ventures, 1555 132nd Ave NE, Bellevue, WA, 98005, USA.
| | - Edward A Wenger
- Institute for Disease Modeling, Intellectual Ventures, 1555 132nd Ave NE, Bellevue, WA, 98005, USA.
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23
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Kay K, Hodel EM, Hastings IM. Improving the role and contribution of pharmacokinetic analyses in antimalarial drug clinical trials. Antimicrob Agents Chemother 2014; 58:5643-9. [PMID: 24982091 PMCID: PMC4187976 DOI: 10.1128/aac.02777-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
It is now World Health Organization (WHO) policy that drug concentrations on day 7 be measured as part of routine assessment in antimalarial drug efficacy trials. The rationale is that this single pharmacological measure serves as a simple and practical predictor of treatment outcome for antimalarial drugs with long half-lives. Herein we review theoretical data and field studies and conclude that the day 7 drug concentration (d7c) actually appears to be a poor predictor of therapeutic outcome. This poor predictive capability combined with the fact that many routine antimalarial trials will have few or no failures means that there appears to be little justification for this WHO recommendation. Pharmacological studies have a huge potential to improve antimalarial dosing, and we propose study designs that use more-focused, sophisticated, and cost-effective ways of generating these data than the mass collection of single d7c concentrations.
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Affiliation(s)
- Katherine Kay
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Eva Maria Hodel
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Ian M Hastings
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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24
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Onyamboko MA, Fanello CI, Wongsaen K, Tarning J, Cheah PY, Tshefu KA, Dondorp AM, Nosten F, White NJ, Day NPJ. Randomized comparison of the efficacies and tolerabilities of three artemisinin-based combination treatments for children with acute Plasmodium falciparum malaria in the Democratic Republic of the Congo. Antimicrob Agents Chemother 2014; 58:5528-36. [PMID: 25001306 PMCID: PMC4135835 DOI: 10.1128/aac.02682-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 07/02/2014] [Indexed: 12/31/2022] Open
Abstract
An open-label, randomized controlled trial was carried out in 2011-2012 in the Democratic Republic of the Congo to test the efficacy, safety, and tolerability of the artemisinin-based combination treatments dihydroartemisinin-piperaquine, amodiaquine-artesunate, and artemether-lumefantrine. Six hundred eighty-four children aged 3 to 59 months with uncomplicated Plasmodium falciparum malaria were randomly allocated to each study arm. Children were hospitalized for 3 days, given supervised treatment, and followed up weekly for 42 days. All regimens were well tolerated and rapidly effective. The median parasitemia clearance half-life was 2.2 h, and half-lives were similar between arms (P=0.19). The PCR-uncorrected cure rates by day 42 were 73.0% for amodiaquine-artesunate, 70.2% for artemether-lumefantrine, and 86.3% for dihydroartemisinin-piperaquine (P=0.001). Early treatment failure occurred in three patients (0.5%), one in each arm. The PCR-corrected cure rates were 93.4% for amodiaquine-artesunate, 92.7% for artemether-lumefantrine, and 94.3% for dihydroartemisinin-piperaquine (P=0.78). The last provided a longer posttreatment prophylactic effect than did the other two treatments. The day 7 plasma concentration of piperaquine was below 30 ng/ml in 47% of the children treated with dihydroartemisinin-piperaquine, and the day 7 lumefantrine concentration was below 280 ng/ml in 37.0% of children who received artemether-lumefantrine. Thus, although cure rates were all satisfactory, they could be improved by increasing the dose. (This study has been registered with the International Standard Randomized Controlled Trial Number Register [www.isrctn.org] under registration no. ISRCTN20984426.).
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Affiliation(s)
- M A Onyamboko
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - C I Fanello
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - K Wongsaen
- Shoklo Malaria Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - J Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - P Y Cheah
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - K A Tshefu
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - A M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - F Nosten
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom Shoklo Malaria Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - N J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - N P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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25
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Interspecies allometric scaling of antimalarial drugs and potential application to pediatric dosing. Antimicrob Agents Chemother 2014; 58:6068-78. [PMID: 25092696 DOI: 10.1128/aac.02538-14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pharmacopeial recommendations for administration of antimalarial drugs are the same weight-based (mg/kg of body weight) doses for children and adults. However, linear calculations are known to underestimate pediatric doses; therefore, interspecies allometric scaling data may have a role in predicting doses in children. We investigated the allometric scaling relationships of antimalarial drugs using data from pharmacokinetic studies in mammalian species. Simple allometry (Y = a × W(b)) was utilized and compared to maximum life span potential (MLP) correction. All drugs showed a strong correlation with clearance (CL) in healthy controls. Insufficient data from malaria-infected species other than humans were available for allometric scaling. The allometric exponents (b) for CL of artesunate, dihydroartemisinin (from intravenous artesunate), artemether, artemisinin, clindamycin, piperaquine, mefloquine, and quinine were 0.71, 0.85, 0.66, 0.83, 0.62, 0.96, 0.52, and 0.40, respectively. Clearance was significantly lower in malaria infection than in healthy (adult) humans for quinine (0.07 versus 0.17 liter/h/kg; P = 0.0002) and dihydroartemisinin (0.81 versus 1.11 liters/h/kg; P = 0.04; power = 0.6). Interpolation of simple allometry provided better estimates of CL for children than MLP correction, which generally underestimated CL values. Pediatric dose calculations based on simple allometric exponents were 10 to 70% higher than pharmacopeial (mg/kg) recommendations. Interpolation of interspecies allometric scaling could provide better estimates than linear scaling of adult to pediatric doses of antimalarial drugs; however, the use of a fixed exponent for CL was not supported in the present study. The variability in allometric exponents for antimalarial drugs also has implications for scaling of fixed-dose combinations.
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Population pharmacokinetics and clinical response for artemether-lumefantrine in pregnant and nonpregnant women with uncomplicated Plasmodium falciparum malaria in Tanzania. Antimicrob Agents Chemother 2014; 58:4583-92. [PMID: 24867986 DOI: 10.1128/aac.02595-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Artemether-lumefantrine (AL) is the first-line treatment for uncomplicated malaria in the second and third trimesters of pregnancy. Its efficacy during pregnancy has recently been challenged due to altered pharmacokinetic (PK) properties in this vulnerable group. The aim of this study was to determine the PK profile of AL in pregnant and nonpregnant women and assess their therapeutic outcome. Thirty-three pregnant women and 22 nonpregnant women with malaria were treated with AL (80/480 mg) twice daily for 3 days. All patients provided five venous plasma samples for drug quantification at random times over 7 days. Inter- and intraindividual variability was assessed, and the effects of covariates were quantified using a nonlinear mixed-effects modeling approach (NONMEM). A one-compartment model with first-order absorption and elimination with linear metabolism from drug to metabolite fitted the data best for both arthemether (AM) and lumefantrine (LF) and their metabolites. Pregnancy status and diarrhea showed a significant influence on LF PK. The relative bioavailability of lumefantrine and its metabolism rate into desmethyl-lumefantrine were, respectively, 34% lower and 78% higher in pregnant women than in nonpregnant patients. The overall PCR-uncorrected treatment failure rates were 18% in pregnant women and 5% in nonpregnant women (odds ratio [OR] = 4.04; P value of 0.22). A high median day 7 lumefantrine concentration was significantly associated with adequate clinical and parasitological response (P = 0.03). The observed reduction in the relative bioavailability of lumefantrine in pregnant women may explain the higher treatment failure in this group, mostly due to lower posttreatment prophylaxis. Hence, a modified treatment regimen of malaria in pregnancy should be considered.
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