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Kouakou YI, Omorou R, Said IB, Lavoignat A, Bonnot G, Bienvenu AL, Picot S. Assessment of quantitative and semi-quantitative biological test methods of artesunate in vitro. Parasite 2022; 29:18. [PMID: 35348455 PMCID: PMC8962658 DOI: 10.1051/parasite/2022019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/11/2022] [Indexed: 11/14/2022] Open
Abstract
Artesunate is the current most potent antimalarial drug widely used for the treatment of malaria. Considering the emergence of artemisinin resistance, several situations may require a simple method for artesunate quantification. We thus developed a quantitative and a semi-quantitative biological method for the determination of artesunate in liquid samples. The tests are based on the measurement of samples’ antimalarial activity on Plasmodium falciparum 3D7 using a modified SYBR Green I drug susceptibility test. For the quantitative test, we established a standard curve that resulted from a dose–response curve and evaluated its performances using controls samples. Whereas the linear regression analysis between artesunate concentration and antimalarial activity showed promising results (linearity range 1.5–24.6 ng/mL, r2 = 0.9373), we found that artesunate content of the controls was significantly overestimated (p = 0.0313). For the semi-quantitative test, we compared the antimalarial activities of samples collected during permeation studies of artesunate to that of a reference (artesunate IC50) by statistical analysis. We demonstrated that antimalarial activities of samples from permeation tests using a powder formulation of artesunate were greater than those of samples from tests using a solution formulation. Bioassays can be simple techniques to assess artesunate in liquid samples, particularly in resource-limited settings. Comparison with reference methods is still recommended when accurate drug quantification is required.
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Affiliation(s)
- Yobouet Ines Kouakou
- Université de Lyon, Malaria Research Unit, ICBMS, UMR 5246 CNRS-INSA-CPE-Université Lyon1, 69622 Villeurbanne, France - Groupement Hospitalier Nord, Institut de Parasitologie et Mycologie Médicale, Hospices Civils de Lyon, 69004 Lyon, France
| | - Roukayatou Omorou
- Université de Lyon, Malaria Research Unit, ICBMS, UMR 5246 CNRS-INSA-CPE-Université Lyon1, 69622 Villeurbanne, France
| | - Ibrahim Bin Said
- Université de Lyon, Malaria Research Unit, ICBMS, UMR 5246 CNRS-INSA-CPE-Université Lyon1, 69622 Villeurbanne, France
| | - Adeline Lavoignat
- Université de Lyon, Malaria Research Unit, ICBMS, UMR 5246 CNRS-INSA-CPE-Université Lyon1, 69622 Villeurbanne, France
| | - Guillaume Bonnot
- Université de Lyon, Malaria Research Unit, ICBMS, UMR 5246 CNRS-INSA-CPE-Université Lyon1, 69622 Villeurbanne, France
| | - Anne-Lise Bienvenu
- Université de Lyon, Malaria Research Unit, ICBMS, UMR 5246 CNRS-INSA-CPE-Université Lyon1, 69622 Villeurbanne, France - Groupement Hospitalier Nord, Service Pharmacie, Hospices Civils de Lyon, 69004 Lyon, France
| | - Stéphane Picot
- Université de Lyon, Malaria Research Unit, ICBMS, UMR 5246 CNRS-INSA-CPE-Université Lyon1, 69622 Villeurbanne, France - Groupement Hospitalier Nord, Institut de Parasitologie et Mycologie Médicale, Hospices Civils de Lyon, 69004 Lyon, France
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2
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Boonyalai N, Thamnurak C, Sai-Ngam P, Ta-Aksorn W, Arsanok M, Uthaimongkol N, Sundrakes S, Chattrakarn S, Chaisatit C, Praditpol C, Fagnark W, Kirativanich K, Chaorattanakawee S, Vanachayangkul P, Lertsethtakarn P, Gosi P, Utainnam D, Rodkvamtook W, Kuntawunginn W, Vesely BA, Spring MD, Fukuda MM, Lanteri C, Walsh D, Saunders DL, Smith PL, Wojnarski M, Sirisopana N, Waters NC, Jongsakul K, Gaywee J. Plasmodium falciparum phenotypic and genotypic resistance profile during the emergence of Piperaquine resistance in Northeastern Thailand. Sci Rep 2021; 11:13419. [PMID: 34183715 PMCID: PMC8238947 DOI: 10.1038/s41598-021-92735-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/15/2021] [Indexed: 11/09/2022] Open
Abstract
Malaria remains a public health problem in Thailand, especially along its borders where highly mobile populations can contribute to persistent transmission. This study aimed to determine resistant genotypes and phenotypes of 112 Plasmodium falciparum isolates from patients along the Thai-Cambodia border during 2013-2015. The majority of parasites harbored a pfmdr1-Y184F mutation. A single pfmdr1 copy number had CVIET haplotype of amino acids 72-76 of pfcrt and no pfcytb mutations. All isolates had a single pfk13 point mutation (R539T, R539I, or C580Y), and increased % survival in the ring-stage survival assay (except for R539I). Multiple copies of pfpm2 and pfcrt-F145I were detected in 2014 (12.8%) and increased to 30.4% in 2015. Parasites containing either multiple pfpm2 copies with and without pfcrt-F145I or a single pfpm2 copy with pfcrt-F145I exhibited elevated IC90 values of piperaquine. Collectively, the emergence of these resistance patterns in Thailand near Cambodia border mirrored the reports of dihydroartemisinin-piperaquine treatment failures in the adjacent province of Cambodia, Oddar Meanchey, suggesting a migration of parasites across the border. As malaria elimination efforts ramp up in Southeast Asia, host nations militaries and other groups in border regions need to coordinate the proposed interventions.
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Affiliation(s)
- Nonlawat Boonyalai
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
| | - Chatchadaporn Thamnurak
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Piyaporn Sai-Ngam
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Winita Ta-Aksorn
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Montri Arsanok
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Nichapat Uthaimongkol
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Siratchana Sundrakes
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Sorayut Chattrakarn
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chaiyaporn Chaisatit
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chantida Praditpol
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Watcharintorn Fagnark
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Kirakarn Kirativanich
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Suwanna Chaorattanakawee
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.,Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Pattaraporn Vanachayangkul
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Paphavee Lertsethtakarn
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Panita Gosi
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Darunee Utainnam
- Royal Thai Army Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Wuttikon Rodkvamtook
- Royal Thai Army Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Worachet Kuntawunginn
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Brian A Vesely
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Michele D Spring
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Mark M Fukuda
- Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Charlotte Lanteri
- Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Douglas Walsh
- Department of Dermatology, Syracuse VA medical center, Syracuse, USA
| | - David L Saunders
- U.S. Army Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Philip L Smith
- Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Mariusz Wojnarski
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Narongrid Sirisopana
- Royal Thai Army Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Norman C Waters
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Krisada Jongsakul
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Jariyanart Gaywee
- Royal Thai Army Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
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Pharmacokinetics and Ex Vivo Antimalarial Activity of Artesunate-Amodiaquine plus Methylene Blue in Healthy Volunteers. Antimicrob Agents Chemother 2020; 64:AAC.01441-19. [PMID: 31907186 DOI: 10.1128/aac.01441-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 12/08/2019] [Indexed: 11/20/2022] Open
Abstract
High rates of artemisinin-based combination therapy (ACT) failures in the treatment of Plasmodium falciparum malaria in Southeast Asia have led to triple-drug strategies to extend the useful life of ACTs. In this study, we determined whether methylene blue [MB; 3,7-bis(dimethylamino)phenothiazin-5-ium chloride hydrate] alters the pharmacokinetics of artesunate-amodiaquine (ASAQ) and enhances the ex vivo antimalarial activity of ASAQ. In an open-label, randomized crossover design, a single oral dose of ASAQ (200 mg AS/540 mg AQ) alone or with MB (325 mg) was administered to 15 healthy Vietnamese volunteers. Serial blood samples were collected up to 28 days after dosing. Pharmacokinetic properties of the drugs were determined by noncompartmental analysis. After drug administration, plasma samples from seven participants were assessed for ex vivo antimalarial activity against the artemisinin-sensitive MRA1239 and the artemisinin-resistant MRA1240 P. falciparum lines, in vitro MB significantly increased the mean area under the curve of the active metabolite of AS, dihydroartemisinin (1,246 ± 473 versus 917 ± 405 ng·h/ml, P = 0.009) but did not alter the pharmacokinetics of AQ, AS, or desethylamodiaquine. Comparing the antimalarial activities of the plasma samples from the participants collected up to 48 h after ASAQ plus MB (ASAQ+MB) and ASAQ dosing against the MRA1239 and MRA1240 lines, MB significantly enhanced the blood schizontocidal activity of ASAQ by 2.0-fold and 1.9-fold, respectively. The ring-stage survival assay also confirmed that MB enhanced the ex vivo antimalarial activity of ASAQ against MRA1240 by 2.9-fold to 3.8-fold, suggesting that the triple-drug combination has the potential to treat artemisinin-resistant malaria and for malaria elimination. (This study has been registered in the Australian New Zealand Clinical Trials Registry [https://anzctr.org.au/] under registration number ACTRN12612001298808.).
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Wojnarski M, Lon C, Vanachayangkul P, Gosi P, Sok S, Rachmat A, Harrison D, Berjohn CM, Spring M, Chaoratanakawee S, Ittiverakul M, Buathong N, Chann S, Wongarunkochakorn S, Waltmann A, Kuntawunginn W, Fukuda MM, Burkly H, Heang V, Heng TK, Kong N, Boonchan T, Chum B, Smith P, Vaughn A, Prom S, Lin J, Lek D, Saunders D. Atovaquone-Proguanil in Combination With Artesunate to Treat Multidrug-Resistant P. falciparum Malaria in Cambodia: An Open-Label Randomized Trial. Open Forum Infect Dis 2019; 6:ofz314. [PMID: 31660398 DOI: 10.1093/ofid/ofz314] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 06/28/2019] [Indexed: 12/16/2022] Open
Abstract
Background Recent artemisinin-combination therapy failures in Cambodia prompted a search for alternatives. Atovaquone-proguanil (AP), a safe, effective treatment for multidrug-resistant Plasmodium falciparum (P.f.), previously demonstrated additive effects in combination with artesunate (AS). Methods Patients with P.f. or mixed-species infection (n = 205) in Anlong Veng (AV; n = 157) and Kratie (KT; n = 48), Cambodia, were randomized open-label 1:1 to a fixed-dose 3-day AP regimen +/-3 days of co-administered artesunate (ASAP). Single low-dose primaquine (PQ, 15 mg) was given on day 1 to prevent gametocyte-mediated transmission. Results Polymerase chain reaction-adjusted adequate clinical and parasitological response at 42 days was 90% for AP (95% confidence interval [CI], 82%-95%) and 92% for ASAP (95% CI, 83%-96%; P = .73). The median parasite clearance time was 72 hours for ASAP in AV vs 56 hours in KT (P < .001) and was no different than AP alone. At 1 week postprimaquine, 7% of the ASAP group carried microscopic gametocytes vs 29% for AP alone (P = .0001). Nearly all P.f. isolates had C580Y K13 propeller artemisinin resistance mutations (AV 99%; KT 88%). Only 1 of 14 treatment failures carried the cytochrome bc1 (Pfcytb) atovaquone resistance mutation, which was not present at baseline. P.f. isolates remained atovaquone sensitive in vitro but cycloguanil resistant, with a triple P.f. dihydrofolate reductase mutation. Conclusions Atovaquone-proguanil remained marginally effective in Cambodia (≥90%) with minimal Pfcytb mutations observed. Treatment failures in the presence of ex vivo atovaquone sensitivity and adequate plasma levels may be attributable to cycloguanil and/or artemisinin resistance. Artesunate co-administration provided little additional blood-stage efficacy but reduced post-treatment gametocyte carriage in combination with AP beyond single low-dose primaquine.
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Affiliation(s)
- Mariusz Wojnarski
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chanthap Lon
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Panita Gosi
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Somethy Sok
- Department of Health, Ministry of National Defense, Phnom Penh, Cambodia
| | - Agus Rachmat
- Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | | | | | - Michele Spring
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.,Henry M. Jackson Foundation, Bethesda, Maryland
| | - Suwanna Chaoratanakawee
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mali Ittiverakul
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Nillawan Buathong
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Soklyda Chann
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | | | | | - Mark M Fukuda
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Hana Burkly
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Vireak Heang
- Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | - Thay Keang Heng
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Nareth Kong
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Threechada Boonchan
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Bolin Chum
- Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | - Philip Smith
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Satharath Prom
- Department of Health, Ministry of National Defense, Phnom Penh, Cambodia
| | - Jessica Lin
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - David Saunders
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.,US Army Medical Materiel Development Activity, Fort Detrick, Maryland
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5
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Quang NN, Chavchich M, Anh CX, Birrell GW, van Breda K, Travers T, Rowcliffe K, Edstein MD. Comparison of the Pharmacokinetics and Ex Vivo Antimalarial Activities of Artesunate-Amodiaquine and Artemisinin-Piperaquine in Healthy Volunteers for Preselection Malaria Therapy. Am J Trop Med Hyg 2018; 99:65-72. [PMID: 29741150 PMCID: PMC6085815 DOI: 10.4269/ajtmh.17-0434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 03/09/2018] [Indexed: 11/07/2022] Open
Abstract
The pharmacokinetics (PK) and ex vivo activity (pharmacodynamics [PD]) of two artemisinin combination therapies (ACTs) (artemisinin-piperaquine [ARN-PPQ] [Artequick®] and artesunate-amodiaquine [ARS-AQ] [Coarsucam™]) in healthy Vietnamese volunteers were compared following 3-day courses of the ACTs for the preselection of the drugs for falciparum malaria therapy. For PK analysis, serial plasma samples were collected from two separate groups of 22 volunteers after ACT administration. Of these volunteers, ex vivo activity was assessed in plasma samples from seven volunteers who received both ACTs. The area under the concentration-time curve (AUC0-∞) was 3.6-fold higher for dihydroartemisinin (active metabolite of ARS) than that for ARN, whereas the AUC0-∞ of desethylamodiaquine (active metabolite of AQ) was 2.0-fold lower than that of PPQ. Based on the 50% inhibitory dilution values of the volunteers' plasma samples collected from 0.25 to 3 hours after the last dose, the ex vivo activity of ARS-AQ was 2.9- to 16.2-fold more potent than that of ARN-PPQ against the drug-sensitive D6 Plasmodium falciparum line. In addition, at 1.5, 4.0, and 24 hours after the last dose, the ex vivo activity of ARS-AQ was 20.8-, 3.5-, and 8.5-fold more potent than that of ARN-PPQ against the ARN-sensitive MRA1239 line. By contrast, at 1.5 hours, the ex vivo activity of ARS-AQ was 5.4-fold more active than that of ARN-PPQ but had similar activities at 4 and 24 hours against the ARN-resistant MRA1240 line. The PK-PD data suggest that ARS-AQ possesses superior antimalarial activity than that of ARN-PPQ and would be the preferred ACT for further in vivo efficacy testing in multidrug-resistant falciparum malaria areas.
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Affiliation(s)
- Nguyen Ngoc Quang
- Institute for Clinical Infectious Diseases, Central Military Hospital 108, Hanoi, Vietnam
| | - Marina Chavchich
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Chu Xuan Anh
- Institute for Clinical Infectious Diseases, Central Military Hospital 108, Hanoi, Vietnam
| | - Geoffrey W. Birrell
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Karin van Breda
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Thomas Travers
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Kerryn Rowcliffe
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Michael D. Edstein
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
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Comparative pharmacokinetics and pharmacodynamics of intravenous artelinate versus artesunate in uncomplicated Plasmodium coatneyi-infected rhesus monkey model. Malar J 2016; 15:453. [PMID: 27599723 PMCID: PMC5011932 DOI: 10.1186/s12936-016-1456-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/28/2016] [Indexed: 11/25/2022] Open
Abstract
Background The US Army designed artelinate/lysine salt (AL) to overcome the instability of sodium artesunate in aqueous solution (AS). To select the most efficacious artemisinin treatment, direct comparison was performed in an uncomplicated non-human primate malaria model. Methods Splenectomized rhesus monkeys were inoculated with Plasmodium coatneyi and on day six, single equimolar loading dose of IV AL (11.8 mg kg−1) or IV AS (8 mg kg−1) were administered followed by 1/2 the first dose once daily for 2 more days. Blood smear were performed twice daily and the number of parasites were counted microscopically. Blood samples were obtained after the first dose within 6 h for pharmacokinetic (PK) and ex vivo pharmacodynamic evaluation by simultaneously measuring plasma drug concentration and anti-malarial activity against Plasmodium falciparum in vitro. Results The anti-P. coatneyi in vivo activity of both compounds were comparable, but the ex vivo anti-P. falciparum potency of the IV AS regimen as administered was sevenfold higher than that of IV AL. Comparing in vivo pharmacodynamics of AL and AS, daily assessed parasite counts showed comparable 99 % parasite clearance times (PC99: 2.03, 1.84 day), parasite clearance rates (5.34, 4.13 per min) and clearance half-life (PCt1/2: 7.79, 10.1 h). This study showed strong and significant inverse correlation between PCt1/2 and t1/2 of AS + DHA, and AUC0–∞ of DHA, and correlated with Vz of AS (r2 > 0.7, p ≤ 0.002). Lastly, following IV AL, there was a modest inverse correlation between PCt1/2 and Cmax (r2 0.6, p ≤ 0.04). Although all tested monkeys recrudesced subsequently, two died following AL regimen before parasite clearance. While the aetiology of those deaths could not be definitively determined, pathologic evidence favoured a sepsis-like syndrome and suggested that severe malaria was more likely than drug toxicity. Conclusion The model demonstrated that both AS and DHA contributed to the anti-malarial activity of IV AS, while IV AL activity was largely restricted to the parent drug. Parasite clearance was strongly and linearly dependent on drug exposure for both artemisinin regimens. However, IV AS had higher ex vivo potency against P. falciparum, leading to an IND filing for GMP manufactured AS in the United States. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1456-6) contains supplementary material, which is available to authorized users.
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Krause A, Dingemanse J, Mathis A, Marquart L, Möhrle JJ, McCarthy JS. Pharmacokinetic/pharmacodynamic modelling of the antimalarial effect of Actelion-451840 in an induced blood stage malaria study in healthy subjects. Br J Clin Pharmacol 2016; 82:412-21. [PMID: 27062080 PMCID: PMC4972157 DOI: 10.1111/bcp.12962] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 03/10/2016] [Accepted: 03/30/2016] [Indexed: 01/22/2023] Open
Abstract
Aims The aim of this study was to use data from an experimental induced blood stage malaria clinical trial to characterize the antimalarial activity of the new compound Actelion‐451840 using pharmacokinetic/pharmacodynamic (PK/PD) modelling. Then, using simulations from the model, the dose and dosing regimen necessary to achieve cure of infection were derived. Methods Eight healthy male subjects were infected with blood stage P. falciparum. After 7 days, a single dose of 500 mg of Actelion‐451840 was administered under fed conditions. Parasite and drug concentrations were sampled frequently. Parasite growth and the relation to drug exposure were estimated using PK/PD modelling. Simulations were then undertaken to derive estimates of the likelihood of achieving cure in different scenarios. Results Actelion‐451840 was safe and well tolerated. Single dose treatment markedly reduced the level of P. falciparum parasitaemia, with a weighted average parasite reduction rate of 73.6 (95% CI 56.1, 96.5) and parasite clearance half‐life of 7.7 h (95% CI 7.3, 8.3). A two compartment PK/PD model with a steep concentration−kill effect predicted maximum effect with a sustained concentration of 10–15 ng ml−1 and cure achieved in 90% of subjects with six once daily doses of 300 mg once daily. Conclusions Actelion‐451840 shows clinical efficacy against P. falciparum infections. The PK/PD model developed from a single proof‐of‐concept study with eight healthy subjects enabled prediction of therapeutic effects, with cure rates with seven daily doses predicted to be equivalent to artesunate monotherapy. Larger doses or more frequent dosing are not predicted to achieve more rapid cure.
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Affiliation(s)
- Andreas Krause
- Department of Clinical Pharmacology, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Jasper Dingemanse
- Department of Clinical Pharmacology, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Alexandre Mathis
- Department of Clinical Pharmacology, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
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Abdul-Ghani R, Basco LK, Beier JC, Mahdy MAK. Inclusion of gametocyte parameters in anti-malarial drug efficacy studies: filling a neglected gap needed for malaria elimination. Malar J 2015; 14:413. [PMID: 26481312 PMCID: PMC4617745 DOI: 10.1186/s12936-015-0936-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 10/09/2015] [Indexed: 11/29/2022] Open
Abstract
Standard anti-malarial drug efficacy and drug resistance assessments neglect the gametocyte parameters in their protocols. With the spread of drug resistance and the absence of clinically proven vaccines, the use of gametocytocidal drugs or drug combinations with transmission-blocking activity is a high priority for malaria control and elimination. However, the limited repertoire of gametocytocidal drugs and induction of gametocytogenesis after treatment with certain anti-malarial drugs necessitate both regular monitoring
of gametocytocidal activities of anti-malarial drugs in clinical use and the effectiveness of candidate gametocytocidal agents. Therefore, updating current protocols of anti-malarial drug efficacy is needed to reflect the effects of anti-malarial drugs or drug combinations on gametocyte carriage and gametocyte density along with asexual parasite density. Developing protocols of anti-malarial drug efficacy that include gametocyte parameters related to both microscopic and submicroscopic gametocytaemias is important if drugs or drug combinations are to be strategically used in transmission-blocking interventions in the context of malaria elimination. The present piece of opinion highlights the challenges in gametocyte detection and follow-up and discuss the need for including the gametocyte parameter in anti-malarial efficacy studies.
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Affiliation(s)
- Rashad Abdul-Ghani
- Department of Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen. .,Tropical Disease Research Center, University of Science and Technology, Sana'a, Yemen.
| | - Leonardo K Basco
- Unité de Recherche 198, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Institut de Recherche pour le Développement, Faculté de Médecine La Timone, Aix-Marseille Université, Marseille, France.
| | - John C Beier
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Mohammed A K Mahdy
- Department of Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen. .,Tropical Disease Research Center, University of Science and Technology, Sana'a, Yemen.
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Ex Vivo Drug Susceptibility Testing and Molecular Profiling of Clinical Plasmodium falciparum Isolates from Cambodia from 2008 to 2013 Suggest Emerging Piperaquine Resistance. Antimicrob Agents Chemother 2015; 59:4631-43. [PMID: 26014942 DOI: 10.1128/aac.00366-15] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/18/2015] [Indexed: 12/26/2022] Open
Abstract
Cambodia's first-line artemisinin combination therapy, dihydroartemisinin-piperaquine (DHA-PPQ), is no longer sufficiently curative against multidrug-resistant Plasmodium falciparum malaria at some Thai-Cambodian border regions. We report recent (2008 to 2013) drug resistance trends in 753 isolates from northern, western, and southern Cambodia by surveying for ex vivo drug susceptibility and molecular drug resistance markers to guide the selection of an effective alternative to DHA-PPQ. Over the last 3 study years, PPQ susceptibility declined dramatically (geomean 50% inhibitory concentration [IC50] increased from 12.8 to 29.6 nM), while mefloquine (MQ) sensitivity doubled (67.1 to 26 nM) in northern Cambodia. These changes in drug susceptibility were significantly associated with a decreased prevalence of P. falciparum multidrug resistance 1 gene (Pfmdr1) multiple copy isolates and coincided with the timing of replacing artesunate-mefloquine (AS-MQ) with DHA-PPQ as the first-line therapy. Widespread chloroquine resistance was suggested by all isolates being of the P. falciparum chloroquine resistance transporter gene CVIET haplotype. Nearly all isolates collected from the most recent years had P. falciparum kelch13 mutations, indicative of artemisinin resistance. Ex vivo bioassay measurements of antimalarial activity in plasma indicated 20% of patients recently took antimalarials, and their plasma had activity (median of 49.8 nM DHA equivalents) suggestive of substantial in vivo drug pressure. Overall, our findings suggest DHA-PPQ failures are associated with emerging PPQ resistance in a background of artemisinin resistance. The observed connection between drug policy changes and significant reduction in PPQ susceptibility with mitigation of MQ resistance supports reintroduction of AS-MQ, in conjunction with monitoring of the P. falciparum mdr1 copy number, as a stop-gap measure in areas of DHA-PPQ failure.
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First-in-humans study of the safety, tolerability, and pharmacokinetics of ACT-451840, a new chemical entity with antimalarial activity. Antimicrob Agents Chemother 2014; 59:935-42. [PMID: 25421475 DOI: 10.1128/aac.04125-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Emerging resistance to antimalarial agents raises the need for new drugs. ACT-451840 is a new compound with potent activity against sensitive and resistant Plasmodium falciparum strains. This was a first-in-humans single-ascending-dose study to investigate the safety, tolerability, and pharmacokinetics of ACT-451840 across doses of 10, 50, 200, and 500 mg in healthy male subjects. In the 200- and 500-mg dose groups, the effect of food was investigated, and antimalarial activity was assessed using an ex vivo bioassay with P. falciparum. No (serious) adverse events leading to discontinuation were reported. At the highest dose level, the peak drug concentration (Cmax) and the area under the plasma concentration-time curve from zero to infinity of ACT-451840 under fasted conditions reached 11.9 ng/ml and 100.6 ng·h/ml, respectively, and these were approximately 13-fold higher under fed conditions. Food did not affect the half-life (approximately 34 h) of the drug, while the Cmax was attained 2.0 and 3.5 h postdose under fasted and fed conditions, respectively. The plasma concentrations estimated by the bioassay were approximately 4-fold higher than those measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Several potentially active metabolites were also identified. ACT-451840 was well tolerated across all doses. Exposure to ACT-451840 significantly increased with food. The bioassay indicated the presence of circulating active metabolites. (This study has been registered at ClinicalTrials.gov under registration no. NCT02186002.).
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Moehrle JJ, Duparc S, Siethoff C, van Giersbergen PLM, Craft JC, Arbe-Barnes S, Charman SA, Gutierrez M, Wittlin S, Vennerstrom JL. First-in-man safety and pharmacokinetics of synthetic ozonide OZ439 demonstrates an improved exposure profile relative to other peroxide antimalarials. Br J Clin Pharmacol 2013; 75:524-37. [PMID: 22759078 PMCID: PMC3558805 DOI: 10.1111/j.1365-2125.2012.04368.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 06/23/2012] [Indexed: 11/29/2022] Open
Abstract
Aims To assess the safety and pharmacokinetics of a new synthetic ozonide antimalarial, OZ439, in a first-in-man, double-blind study in healthy volunteers. Methods OZ439 was administered as single oral daily doses of a capsule formulation (50–1200 mg) or an oral dispersion (400–1600 mg, fed and fasted states) and for up to 3 days as an oral dispersion (200–800 mg day−1). Plasma concentrations of OZ439 and its metabolites were measured by LC-MS. Results The pharmacokinetic (PK) profile of OZ439 was characterized by a tmax of around 3 h, followed by a multiphasic profile with a terminal half-life of 25–30 h. The PK parameters were approximately dose proportional for each group and profiles of the metabolites followed a similar pattern to that of the parent compound. Following dosing for 3 days, accumulation was less than two-fold but steady-state was not achieved. In the presence of food, no effect was observed on the t1/2 of OZ439 while the exposure was increased by 3 to 4.5-fold. Exposure was higher and inter-subject variability was reduced when OZ439 was administered as an oral dispersion compared with a capsule. The urinary clearance of OZ439 and its metabolites was found to be negligible and OZ439 did not induce CYP3A4. The antimalarial activity profiles of a subset of serum samples suggested that the major antimalarial activity originated from OZ439 rather than from any of the metabolites. Conclusion The safety and pharmacokinetic profile of OZ439 merits progression to phase 2a proof of concept studies in the target population of acute uncomplicated malaria.
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In vitro antimalarial activity and drug interactions of fenofibric acid. Antimicrob Agents Chemother 2012; 56:2814-8. [PMID: 22430967 DOI: 10.1128/aac.05076-11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum has developed resistance to most available treatments, underscoring the need for novel antimalarial drugs. Fibrates are lipid-modifying agents used to reduce morbidity and mortality associated with cardiovascular disease. They may have antimalarial activity through modulation of P-glycoprotein and ATP-binding cassette subfamily A member (ABC-1)-mediated nutrient transport and/or via a putative peroxisome proliferator-activated receptor alpha-like protein. We therefore examined in vitro antimalarial activities of fibrates and their interactions with chloroquine and dihydroartemisinin in chloroquine-sensitive (3D7) and chloroquine-resistant (W2mef) strains of P. falciparum using the conventional isotopic assay microtechnique. A bioassay was used to assess inhibition activities of human plasma after therapeutic fenofibrate doses. Fenofibric acid, the main metabolite of fenofibrate, was the most potent of the fibrates tested, with mean 50% inhibitory concentrations of 152 nM and 1,120 nM for chloroquine-sensitive and -resistant strains, respectively. No synergistic interaction between fibrates and chloroquine or dihydroartemisinin was observed. Plasma fenofibric acid concentrations, quantified by high-performance liquid chromatography in seven healthy volunteers after treatment (mean, 15.3 mg/liter, or 48 μM), inhibited P. falciparum. BLAST analysis revealed the likely presence of an ABC-1 transporter homolog in P. falciparum. Our findings demonstrate that fenofibric acid has activity similar to the activities of conventional antimalarial drugs at concentrations well below those achieved after therapeutic doses. It may inhibit P. falciparum growth by inhibiting intracellular lipid transport.
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Absolute bioavailability of cis-mirincamycin and trans-mirincamycin in healthy rhesus monkeys and ex vivo antimalarial activity against Plasmodium falciparum. Antimicrob Agents Chemother 2011; 55:5881-6. [PMID: 21947400 DOI: 10.1128/aac.01619-10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pharmacokinetics, oral bioavailability, and ex vivo antimalarial activity of mirincamycin isomers in a healthy rhesus monkey model were assessed to support lead optimization of novel nonhemolytic drugs for radical cure and causal prophylaxis of malaria. Fourteen male rhesus monkeys were randomized to four groups, which included cis and trans isomers by the oral and intravenous routes, with vehicle-only controls for each dosing route. Concentration-time data were collected for 7 days and were analyzed by noncompartmental analysis. cis-Mirincamycin had an absolute oral bioavailability of 13.6%, which was slightly higher than that of trans-mirincamycin (11.7%), but this difference was not statistically significant. There was a statistically significant difference between the area under the concentration-time curve from zero to 48 h (AUC(0-48)) of cis-mirincamycin and that of trans-mirincamycin after oral dosing. When cultured in vitro with the W2 clone of Plasmodium falciparum, the 50% inhibitory concentrations for cis-mirincamycin, trans-mirincamycin, and dihydroartemisinin were 11,300, 12,300, and 2.30 nM, respectively. However, when dosed primate plasma was cultured ex vivo against the W2 clone, both isomers had much greater relative potencies than their in vitro activities relative to results for dihydroartemisinin, an increase of approximately 100-fold for the cis isomer and 150-fold for the trans isomer. Further, oral ex vivo activity was significantly higher than intravenous activity for both isomers, particularly during the first 90 min following dosing, suggesting the first-pass formation of one or more metabolites with blood-stage antimalarial activity. Identification of the metabolic pathways and metabolites may help to further delineate the properties of this class of drugs with previously demonstrated liver-stage antimalarial activity.
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Navaratnam V, Ramanathan S, Wahab MSA, Siew Hua G, Mansor SM, Kiechel JR, Vaillant M, Taylor WRJ, Olliaro P. Tolerability and pharmacokinetics of non-fixed and fixed combinations of artesunate and amodiaquine in Malaysian healthy normal volunteers. Eur J Clin Pharmacol 2009; 65:809-21. [PMID: 19404632 PMCID: PMC2714898 DOI: 10.1007/s00228-009-0656-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 04/02/2009] [Indexed: 11/25/2022]
Abstract
Objective There is limited pharmacokinetic data available for the combination artesunate + amodiaquine, which is used widely to treat uncomplicated malaria. This study examines the bioavailability and tolerability of a fixed (200 mg artesunate + 540 mg amodiaquine) and loose (200 mg + 612 mg) combination with a 2×2 cross-over design in 24 healthy volunteers. Methods Parent compounds and metabolites [dihydroartemisinin (DHA) and desethylamodiaquine (DEAQ)] were measured by high-performance liquid chromatography–electrochemical detection, and the area under the curve (AUC)0-t and Cmax were compared by an analysis of variance (ANOVA) based on geometric least square means using the Schuirmann two one-sided test. Results The AUC0-t for total DHA and DEAQ were 1522 ± 633 and 30021 ± 14211 ng h/ml for the fixed products and 1688 ± 767 and 40261 ± 19824 ng h/ml (mean ± standard deviation) for the loose products. The ANOVA showed no statistical differences except for sequence effect for DHA. The values obtained with the fixed product were within the 125% bioequivalent limits but extend below the 80% bioequivalence limits. Conclusion Both combinations were well tolerated and had comparable pharmacokinetic profiles; differences are unlikely to be clinically relevant. Electronic supplementary material The online version of this article (doi:10.1007/s00228-009-0656-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Visweswaran Navaratnam
- National Center for Drug Research (CRD), Universiti Sains Malaysia (USM), 11800 Minden, Pulau Pinang, Penang Malaysia
| | - Surash Ramanathan
- National Center for Drug Research (CRD), Universiti Sains Malaysia (USM), 11800 Minden, Pulau Pinang, Penang Malaysia
| | - Mohd Suhaimi Ab. Wahab
- Pharmacology Laboratory, CTU-Clinical Trial Unit, School of Medical Sciences, Health Campus, Hospital Universiti Sains Malaysia (HUSM), Kubang Kerian, Kota Bharu, 16150 Kelantan Malaysia
| | - Gan Siew Hua
- Pharmacology Laboratory, CTU-Clinical Trial Unit, School of Medical Sciences, Health Campus, Hospital Universiti Sains Malaysia (HUSM), Kubang Kerian, Kota Bharu, 16150 Kelantan Malaysia
| | - Sharif Mahsufi Mansor
- National Center for Drug Research (CRD), Universiti Sains Malaysia (USM), 11800 Minden, Pulau Pinang, Penang Malaysia
| | - Jean-René Kiechel
- Drugs for Neglected Diseases initiative (DNDi), 15 Chemin Louis-Dunant, Geneva, 1202 Switzerland
| | - Michel Vaillant
- Centre for Health Studies, Public Research Centre–Health, 18 Dicks Street, 1417 Luxembourg, Germany
- Unité 3677, Bases thérapeutiques des inflammations, Université Victor Segalen Bordeaux II, Bordeaux, France
| | - Walter R. J. Taylor
- Service de Médicine Internationale et Humanitaire, Hôpitaux Universitaires de Genève, Genève 14, Suisse
| | - Piero Olliaro
- UNICEF/UNDP/WB/WHO Special Programme for Research & Training in Tropical Diseases (TDR), 20, Avenue Appia, Geneva 27, 1211 Switzerland
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Bienvenu AL, Ferrandiz J, Kaiser K, Latour C, Picot S. Artesunate-erythropoietin combination for murine cerebral malaria treatment. Acta Trop 2008; 106:104-8. [PMID: 18359468 DOI: 10.1016/j.actatropica.2008.02.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 01/29/2008] [Accepted: 02/04/2008] [Indexed: 01/08/2023]
Abstract
Cerebral malaria is the most severe and rapidly fatal complication of Plasmodium falciparum infection. Despite appropriate anti-malarial treatment using quinine or artemisinin derivatives, 10-20% of mortality still occurs during the acute phase. To improve cerebral malaria outcome, adjunctive therapies are clearly needed. Most experiments in this area have been dedicated to immuno-modulation with various successes. Since erythropoietin has been shown to be highly effective in human ischemic stroke and in murine cerebral malaria, we addressed the issue of cerebral malaria outcome improvement by erythropoietin-artesunate drug combination. Compared to the previous study using erythropoietin high doses at the early beginning of the disease, erythropoietin treatment was decreased by six-fold and delayed to the pre-mortem phase. We studied effects on survival and on clinical recovery of the drug combination given from day 6 to day 8 post-infection to CBA/J mice infected by Plasmodium berghei ANKA. We showed that the artesunate-erythropoietin drug combination led to clinical recovery 24 h earlier for surviving mice, and to increase in the global survival rate compared to artesunate monotherapy (p<0.01). Since erythropoietin has no effect on parasite clearance, it could be stated that this drug combination is efficient and that erythropoietin could be a lead for the implementation of a new adjunctive therapy during the acute phase of cerebral malaria.
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McGready R, Stepniewska K, Lindegardh N, Ashley EA, La Y, Singhasivanon P, White NJ, Nosten F. The pharmacokinetics of artemether and lumefantrine in pregnant women with uncomplicated falciparum malaria. Eur J Clin Pharmacol 2006; 62:1021-31. [PMID: 17053895 DOI: 10.1007/s00228-006-0199-7] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2006] [Accepted: 08/07/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To determine the pharmacokinetic properties of artemether and lumefantrine (AL) in pregnant women with recrudescent uncomplicated multi-drug resistant falciparum malaria. METHODS Pregnant women who had recurrence of parasitaemia following 7 days supervised quinine treatment were treated with AL. Serial blood samples were taken over a 7-day period, and pharmacokinetic parameters were estimated. For lumefantrine, these data were compared in a population pharmacokinetic model with data from non-pregnant, mainly male adults with acute malaria. RESULTS The pregnant women (five in the second trimester and eight in the third trimester) had lower concentrations of artemether, dihydroartemisinin and lumefantrine, and the elimination of lumefantrine in pregnant women was more rapid than reported previously in non-pregnant adults. CONCLUSION Pregnancy is associated with reduced plasma concentrations of both artemether and lumefantrine. This is likely to be of therapeutic significance as plasma concentrations of lumefantrine, after elimination of artemether, are an important determinant of cure. Further studies are needed to determine the optimum dose regimen of artemether-lumefantrine in pregnancy.
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Affiliation(s)
- Rose McGready
- Shoklo Malaria Research Unit, P.O. Box 46, Mae Sot, Tak, Thailand
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Abstract
Artemisinins were discovered to be highly effective antimalarial drugs shortly after the isolation of the parent artemisinin in 1971 in China. These compounds combine potent, rapid antimalarial activity with a wide therapeutic index and an absence of clinically important resistance. Artemisinin containing regimens meet the urgent need to find effective treatments for multidrug resistant malaria and have recently been advocated for widespread deployment. Comparative trials of artesunate and quinine for severe malaria are in progress to see if the persistently high mortality of this condition can be reduced.
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Affiliation(s)
- C J Woodrow
- Department of Cellular and Molecular Medicine, Infectious Diseases, St George's Hospital Medical School, Tooting, London, UK
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Noedl H, Teja-Isavadharm P, Miller RS. Nonisotopic, semiautomated plasmodium falciparum bioassay for measurement of antimalarial drug levels in serum or plasma. Antimicrob Agents Chemother 2004; 48:4485-7. [PMID: 15504891 PMCID: PMC525391 DOI: 10.1128/aac.48.11.4485-4487.2004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2004] [Revised: 05/24/2004] [Accepted: 07/22/2004] [Indexed: 11/20/2022] Open
Abstract
A simple, nonisotopic, semiautomated bioassay for the measurement of antimalarial drug levels in plasma or serum based on the quantitation of histidine-rich protein II in malaria culture is presented. The assay requires only small sample volumes and was found to be highly sensitive and reproducible. The results closely paralleled those obtained with isotopic bioassays (R = 0.988, P < 0.001) and high-performance liquid chromatography-electrochemical detection (R = 0.978, P < 0.001).
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Affiliation(s)
- Harald Noedl
- Department of Specific Prophylaxis and Tropical Medicine, Institute of Pathophysiology, University of Vienna, Kinderspitalgasse 15, A-1095 Vienna, Austria.
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