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Haghiri A, Price DJ, Fitzpatrick P, Dini S, Rajasekhar M, Fanello C, Tarning J, Watson J, White NJ, Simpson JA. Evidence Based Optimal Dosing of Intravenous Artesunate in Children with Severe Falciparum Malaria. Clin Pharmacol Ther 2023; 114:1304-1312. [PMID: 37666798 DOI: 10.1002/cpt.3041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/26/2023] [Indexed: 09/06/2023]
Abstract
The majority of deaths from malaria are in young African children. Parenteral artesunate (ARS) is the first-line treatment for severe falciparum malaria. Since 2015, the World Health Organization has recommended individual doses of 3 mg/kg for children weighing < 20 kg. Recently, the US Food and Drug Administration (FDA) has challenged this recommendation, based on a simulated pediatric population, and argued for a lower dose in younger children (2.4 mg/kg). In this study, we performed population pharmacokinetic (PK) modeling of plasma concentration data from 80 children with severe falciparum malaria in the Democratic Republic of Congo who were given 2.4 mg/kg of ARS intravenously. Bayesian hierarchical modeling and a two-compartment parent drug-metabolite PK model for ARS were used to describe the population PKs of ARS and its main biologically active metabolite dihydroartemisinin. We then generated a virtual population representative of the target population in which the drug is used and simulated the total first-dose exposures. Our study shows that the majority of younger children given the lower 2.4 mg/kg dose of intravenous ARS do not reach the same drug exposures as older children above 20 kg. This finding supports withdrawal of the FDA's recent lower ARS dose recommendation as parenteral ARS is an extremely safe and well-tolerated drug and there is potential for harm from underdosing in this rapidly lethal infection.
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Affiliation(s)
- Ali Haghiri
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- School of Engineering, University of Leicester, Leicester, UK
| | - David J Price
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- Doherty Institute for Infection and Immunity, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Phoebe Fitzpatrick
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Saber Dini
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Megha Rajasekhar
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Caterina Fanello
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - James Watson
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
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Pal C. Redox modulating small molecules having antimalarial efficacy. Biochem Pharmacol 2023; 218:115927. [PMID: 37992998 DOI: 10.1016/j.bcp.2023.115927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/24/2023]
Abstract
The search for effective antimalarial agents remains a critical priority because malaria is widely spread and drug-resistant strains are becoming more prevalent. In this review, a variety of small molecules capable of modulating redox processes were showcased for their potential as antimalarial agents. The compounds were designed to target the redox balance of Plasmodium parasites, which has a pivotal function in their ability to survive and multiply within the host organism. A thorough screening method was utilized to assess the effectiveness of these compounds against both drug-sensitive and drug-resistant strains of Plasmodium falciparum, the malaria-causing parasite. The results revealed that several of the tested compounds exhibited significant effectiveness against malaria, displaying IC50 values at a low micromolar range. Furthermore, these compounds displayed promising selectivity for the parasite, as they exhibited low cytotoxicity towards mammalian cells. Thorough mechanistic studies were undertaken to clarify how the active compounds exert their mode of action. The findings revealed that these compounds disrupted the parasites' redox balance, causing oxidative stress and interfering with essential cellular functions. Additionally, the compounds showed synergistic effects when combined with existing antimalarial drugs, suggesting their potential for combination therapies to combat drug resistance. Overall, this study highlights the potential of redox-modulating small molecules as effective antimalarial agents. The identified compounds demonstrate promising antimalarial activity, and their mechanism of action offers insights into targeting the redox balance of Plasmodium parasites. Further optimization and preclinical studies are warranted to determine their efficacy, safety, and potential for clinical development as novel antimalarial therapeutics.
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Affiliation(s)
- Chinmay Pal
- Department of Chemistry, Gobardanga Hindu College, North 24 Parganas, West Bengal 743273, India.
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Unger HW, Acharya S, Arnold L, Wu C, van Eijk AM, Gore-Langton GR, Ter Kuile FO, Lufele E, Chico RM, Price RN, Moore BR, Thriemer K, Rogerson SJ. The effect and control of malaria in pregnancy and lactating women in the Asia-Pacific region. Lancet Glob Health 2023; 11:e1805-e1818. [PMID: 37858590 DOI: 10.1016/s2214-109x(23)00415-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/10/2023] [Accepted: 08/23/2023] [Indexed: 10/21/2023]
Abstract
Half of all pregnancies at risk of malaria worldwide occur in the Asia-Pacific region, where Plasmodium falciparum and Plasmodium vivax co-exist. Despite substantial reductions in transmission, malaria remains an important cause of adverse health outcomes for mothers and offspring, including pre-eclampsia. Malaria transmission is heterogeneous, and infections are commonly subpatent and asymptomatic. High-grade antimalarial resistance poses a formidable challenge to malaria control in pregnancy in the region. Intermittent preventive treatment in pregnancy reduces infection risk in meso-endemic New Guinea, whereas screen-and-treat strategies will require more sensitive point-of-care tests to control malaria in pregnancy. In the first trimester, artemether-lumefantrine is approved, and safety data are accumulating for other artemisinin-based combinations. Safety of novel antimalarials to treat artemisinin-resistant P falciparum during pregnancy, and of 8-aminoquinolines during lactation, needs to be established. A more systematic approach to the prevention of malaria in pregnancy in the Asia-Pacific is required.
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Affiliation(s)
- Holger W Unger
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Department of Obstetrics and Gynaecology, Royal Darwin Hospital, Tiwi, NT, Australia; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Sanjaya Acharya
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Lachlan Arnold
- Royal Melbourne Hospital Clinical School, The University of Melbourne, Parkville, VIC, Australia
| | - Connie Wu
- Royal Melbourne Hospital Clinical School, The University of Melbourne, Parkville, VIC, Australia
| | - Anna Maria van Eijk
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Georgia R Gore-Langton
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Feiko O Ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Elvin Lufele
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Vector-Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - R Matthew Chico
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Brioni R Moore
- Curtin Medical School, Curtin University, Bentley, WA, Australia; Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia; Telethon Kids Institute, Perth Children's Hospital, Nedlands, WA, Australia
| | - Kamala Thriemer
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Stephen J Rogerson
- Department of Infectious Diseases, University of Melbourne, The Doherty Institute, Melbourne, VIC, Australia; Department of Medicine, University of Melbourne, The Doherty Institute, Melbourne, VIC, Australia
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Moreira FDL, Benzi JRDL, Pinto L, Thomaz MDL, Duarte G, Lanchote VL. Optimizing Therapeutic Drug Monitoring in Pregnant Women: A Critical Literature Review. Ther Drug Monit 2023; 45:159-172. [PMID: 36127797 DOI: 10.1097/ftd.0000000000001039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/18/2022] [Indexed: 01/20/2023]
Abstract
BACKGROUND More than 90% of pregnant women take at least one drug during pregnancy. Drug dose adjustments during pregnancy are sometimes necessary due to various pregnancy-induced physiological alterations frequently associated with lower plasma concentrations. However, the clinical relevance or benefits of therapeutic drug monitoring (TDM) in pregnant women have not been specifically studied. Clinical pharmacokinetic studies in pregnant women are incredibly challenging for many reasons. Despite this, regulatory agencies have made efforts to encourage the inclusion of this population in clinical trials to achieve more information on the pharmacotherapy of pregnant women. This review aims to provide support for TDM recommendations and dose adjustments in pregnant women. METHODS The search was conducted after a predetermined strategy on PubMed and Scopus databases using the MeSH term "pregnancy" alongside other terms such as "Pregnancy and dose adjustment," "Pregnancy and therapeutic drug monitoring," "Pregnancy and PBPK," "Pregnancy and pharmacokinetics," and "Pregnancy and physiological changes." RESULTS The main information on TDM in pregnant women is available for antiepileptics, antipsychotics, antidepressants, antibiotics, antimalarials, and oncologic and immunosuppressive drugs. CONCLUSIONS More data are needed to support informed benefit-risk decision making for the administration of drugs to pregnant women. TDM and/or pharmacokinetic studies could ensure that pregnant women receive an adequate dosage of an active drug. Mechanistic modeling approaches potentially could increase our knowledge about the pharmacotherapy of this special population, and they could be used to better design dosage regimens.
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Affiliation(s)
- Fernanda de Lima Moreira
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo; and
| | - Jhohann Richard de Lima Benzi
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo; and
| | - Leonardo Pinto
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo; and
| | - Matheus de Lucca Thomaz
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo; and
| | - Geraldo Duarte
- Department of Obstetrics and Gynecology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Vera Lucia Lanchote
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo; and
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Hanboonkunupakarn B, Tarning J, Pukrittayakamee S, Chotivanich K. Artemisinin resistance and malaria elimination: Where are we now? Front Pharmacol 2022; 13:876282. [PMID: 36210819 PMCID: PMC9538393 DOI: 10.3389/fphar.2022.876282] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/22/2022] [Indexed: 11/24/2022] Open
Abstract
The emergence of artemisinin resistance is a major obstacle to the global malaria eradication/elimination programs. Artemisinin is a very fast-acting antimalarial drug and is the most important drug in the treatment of severe and uncomplicated malaria. For the treatment of acute uncomplicated falciparum malaria, artemisinin derivatives are combined with long half-life partner drugs and widely used as artemisinin-based combination therapies (ACTs). Some ACTs have shown decreased efficacy in the Southeast Asian region. Fortunately, artemisinin has an excellent safety profile and resistant infections can still be treated successfully by modifying the ACT. This review describes the pharmacological properties of ACTs, mechanisms of artemisinin resistance and the potential changes needed in the treatment regimens to overcome resistance. The suggested ACT modifications are extension of the duration of the ACT course, alternating use of different ACT regimens, and addition of another antimalarial drug to the standard ACTs (Triple-ACT). Furthermore, a malaria vaccine (e.g., RTS,S vaccine) could be added to mass drug administration (MDA) campaigns to enhance the treatment efficacy and to prevent further artemisinin resistance development. This review concludes that artemisinin remains the most important antimalarial drug, despite the development of drug-resistant falciparum malaria.
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Affiliation(s)
- Borimas Hanboonkunupakarn
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- 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, United Kingdom
| | - Sasithon Pukrittayakamee
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- The Royal Society of Thailand, Bangkok, Thailand
| | - Kesinee Chotivanich
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- The Royal Society of Thailand, Bangkok, Thailand
- *Correspondence: Kesinee Chotivanich,
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Fanello C, Hoglund RM, Lee SJ, Kayembe D, Ndjowo P, Kabedi C, Badjanga BB, Niamyim P, Tarning J, Woodrow C, Gomes M, Day NP, White NJ, Onyamboko MA. Pharmacokinetic Study of Rectal Artesunate in Children with Severe Malaria in Africa. Antimicrob Agents Chemother 2021; 65:e02223-20. [PMID: 33526485 PMCID: PMC8097454 DOI: 10.1128/aac.02223-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/14/2021] [Indexed: 11/20/2022] Open
Abstract
When severe malaria is suspected in children, the WHO recommends pretreatment with a single rectal dose of artesunate before referral to an appropriate facility. This was an individually randomized, open-label, 2-arm, crossover clinical trial in 82 Congolese children with severe falciparum malaria to characterize the pharmacokinetics of rectal artesunate. At admission, children received a single dose of rectal artesunate (10 mg/kg of body weight) followed 12 h later by intravenous artesunate (2.4 mg/kg) or the reverse order. All children also received standard doses of intravenous quinine. Artesunate and dihydroartemisinin were measured at 11 fixed intervals, following 0- and 12-h drug administrations. Clinical, laboratory, and parasitological parameters were measured. After rectal artesunate, artesunate and dihydroartemisinin showed large interindividual variability (peak concentrations of dihydroartemisinin ranged from 5.63 to 8,090 nM). The majority of patients, however, reached previously suggested in vivo IC50 and IC90 values (98.7% and 92.5%, respectively) of combined concentrations of artesunate and dihydroartemisinin between 15 and 30 min after drug administration. The median (interquartile range [IQR]) time above IC50 and IC90 was 5.68 h (2.90 to 6.08) and 2.74 h (1.52 to 3.75), respectively. The absolute rectal bioavailability (IQR) was 25.6% (11.7 to 54.5) for artesunate and 19.8% (10.3 to 35.3) for dihydroartemisinin. The initial 12-h parasite reduction ratio was comparable between rectal and intravenous artesunate: median (IQR), 84.3% (50.0 to 95.4) versus 69.2% (45.7 to 93.6), respectively (P = 0.49). Despite large interindividual variability, rectal artesunate can initiate and sustain rapid parasiticidal activity in most children with severe falciparum malaria while they are transferred to a facility where parenteral artesunate is available. (This study has been registered at ClinicalTrials.gov under identifier NCT02492178.).
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Affiliation(s)
- Caterina Fanello
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Richard M Hoglund
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sue J Lee
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Daddy Kayembe
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Pauline Ndjowo
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Charlie Kabedi
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Benjamin B Badjanga
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Phettree Niamyim
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Charles Woodrow
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Melba Gomes
- World Health Organization, Geneva, Switzerland
| | - Nick P Day
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Marie A Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
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Piperaquine Pharmacokinetics during Intermittent Preventive Treatment for Malaria in Pregnancy. Antimicrob Agents Chemother 2021; 65:AAC.01150-20. [PMID: 33361303 PMCID: PMC8092554 DOI: 10.1128/aac.01150-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/16/2020] [Indexed: 11/20/2022] Open
Abstract
Dihydroartemisinin-piperaquine (DP) is a long-acting artemisinin combination treatment that provides effective chemoprevention and has been proposed as an alternative antimalarial drug for intermittent preventive therapy in pregnancy (IPTp). Several pharmacokinetic studies have shown that dose adjustment may not be needed for the treatment of malaria in pregnancy with DP. Dihydroartemisinin-piperaquine (DP) is a long-acting artemisinin combination treatment that provides effective chemoprevention and has been proposed as an alternative antimalarial drug for intermittent preventive therapy in pregnancy (IPTp). Several pharmacokinetic studies have shown that dose adjustment may not be needed for the treatment of malaria in pregnancy with DP. However, there are limited data on the optimal dosing for IPTp. This study aimed to evaluate the population pharmacokinetics of piperaquine given as IPTp in pregnant women. Pregnant women were enrolled in clinical trials conducted in Kenya and Indonesia and treated with standard 3-day courses of DP, administered in 4- to 8-week intervals from the second trimester until delivery. Pharmacokinetic blood samples were collected for piperaquine drug measurements before each treatment round, at the time of breakthrough symptomatic malaria, and at delivery. Piperaquine population pharmacokinetic properties were investigated using nonlinear mixed-effects modeling with a prior approach. In total, data from 366 Kenyan and 101 Indonesian women were analyzed. The pharmacokinetic properties of piperaquine were adequately described using a flexible transit absorption (n = 5) followed by a three-compartment disposition model. Gestational age did not affect the pharmacokinetic parameters of piperaquine. After three rounds of monthly IPTp, 9.45% (95% confidence interval [CI], 1.8 to 26.5%) of pregnant women had trough piperaquine concentrations below the suggested target concentration (10.3 ng/ml). Translational simulations suggest that providing the full treatment course of DP at monthly intervals provides sufficient protection to prevent malaria infection. Monthly administration of DP has the potential to offer optimal prevention of malaria during pregnancy. (This study has been registered at ClinicalTrials.gov under identifier NCT01669941 and in the ISRCTN under number ISRCTN34010937.)
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Clark RL. Teratogen update: Malaria in pregnancy and the use of antimalarial drugs in the first trimester. Birth Defects Res 2020; 112:1403-1449. [PMID: 33079495 DOI: 10.1002/bdr2.1798] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 02/04/2023]
Abstract
Malaria is a particular problem in pregnancy because of enhanced sensitivity, the possibility of placental malaria, and adverse effects on pregnancy outcome. Artemisinin-containing combination therapies (ACTs) are the most effective antimalarials known. WHO recommends 7-day quinine therapy for uncomplicated Plasmodium falciparum malaria in the first trimester despite the superior tolerability and efficacy of 3-day ACT regimens because artemisinins caused embryolethality and/or cardiovascular malformations at relatively low doses in rats, rabbits, and monkeys. The developmental toxicity of artesunate, artemether, and DHA were similar in rats but artesunate was embryotoxic at lower doses in rabbits (5 mg/kg/day) than artemether (no effect level = 25 mg/kg/day). In clinical studies in Africa, treatment with artemether-lumefantrine in the first trimester was observed to be highly efficacious and the miscarriage rate (≤3.1%) was similar to no antimalarial treatment (2.6%). When data from the first-trimester use of largely artesunate-based therapies in Thailand were pooled together, there was no difference in miscarriage rate compared to quinine. However, individually, artesunate-mefloquine was associated with a higher miscarriage rate (15/71 = 21%) compared to other artemisinin-based therapies including 7-day artesunate + clindamycin (2/50 = 4%) and quinine (92/842 = 11%). Thus, appropriate statistical comparisons of individual ACT groups are needed prior to assuming that they all have the same risk for developmental toxicity. Current limitations in the assessment of the safety of ACTs in the first trimester are a lack of exposures early in gestation (gestational weeks 6-7), limited postnatal evaluation for cardiovascular malformations, and the pooling of all ACTs for the assessment of risk.
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Affiliation(s)
- Robert L Clark
- Artemis Pharmaceutical Research, Saint Augustine, Florida, USA
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Moore BR, Davis TM. Updated pharmacokinetic considerations for the use of antimalarial drugs in pregnant women. Expert Opin Drug Metab Toxicol 2020; 16:741-758. [PMID: 32729740 DOI: 10.1080/17425255.2020.1802425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION The association between pregnancy and altered drug pharmacokinetic (PK) properties is acknowledged, as is its impact on drug plasma concentrations and thus therapeutic efficacy. However, there have been few robust PK studies of antimalarial use in pregnancy. Given that inadequate dosing for prevention or treatment of malaria in pregnancy can result in negative maternal/infant outcomes, along with the potential to select for parasite drug resistance, it is imperative that reliable pregnancy-specific dosing recommendations are established. AREAS COVERED PK studies of antimalarial drugs in pregnancy. The present review summarizes the efficacy and PK properties of WHO-recommended therapies used in pregnancy, with a focus on PK studies published since 2014. EXPERT OPINION Changes in antimalarial drug disposition in pregnancy are well described, yet pregnant women continue to receive treatment regimens optimized for non-pregnant adults. Contemporary in silico modeling has recently identified a series of alternative dosing regimens that are predicted to provide optimal therapeutic efficacy for pregnant women.
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Affiliation(s)
- Brioni R Moore
- School of Pharmacy and Biomedical Sciences, Curtin University , Bentley, Western Australia, Australia.,Medical School, University of Western Australia , Crawley, Western Australia, Australia
| | - Timothy M Davis
- Medical School, University of Western Australia , Crawley, Western Australia, Australia
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D'Alessandro S, Menegola E, Parapini S, Taramelli D, Basilico N. Safety of Artemisinin Derivatives in the First Trimester of Pregnancy: A Controversial Story. Molecules 2020; 25:molecules25153505. [PMID: 32752056 PMCID: PMC7435965 DOI: 10.3390/molecules25153505] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/27/2020] [Accepted: 07/30/2020] [Indexed: 12/31/2022] Open
Abstract
Artemisinin combination therapy (ACT) is recommended by the World Health Organization (WHO) as first line treatment for uncomplicated malaria both in adults and children. During pregnancy, ACT is considered safe only in the second and third trimester, since animal studies have demonstrated that artemisinin derivatives can cause foetal death and congenital malformation within a narrow time window in early embryogenesis. During this period, artemisinin derivatives induce defective embryonic erythropoiesis and vasculogenesis/angiogenesis in experimental models. However, clinical data on the safety profile of ACT in pregnant women have not shown an increased risk of miscarriage, stillbirth, or congenital malformation, nor low birth weight, associated with exposure to artemisinins in the first trimester. Although further studies are needed, the evidence collected up to now is prompting the WHO towards a change in the guidelines for the treatment of uncomplicated malaria, allowing the use of ACT also in the first trimester of pregnancy.
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Affiliation(s)
- Sarah D'Alessandro
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133 Milan, Italy
| | - Elena Menegola
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, 20133 Milan, Italy
| | - Silvia Parapini
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, 20133 Milan, Italy
| | - Donatella Taramelli
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan, Italy
| | - Nicoletta Basilico
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133 Milan, Italy
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Birgersson S, Valea I, Tinto H, Traore-Coulibaly M, Toe LC, Hoglund RM, Van Geertruyden JP, Ward SA, D’Alessandro U, Abelö A, Tarning J. Population pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant women with uncomplicated Plasmodium falciparum malaria in Burkina Faso: an open label trial. Wellcome Open Res 2019; 4:45. [PMID: 32025570 PMCID: PMC6974929 DOI: 10.12688/wellcomeopenres.14849.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2019] [Indexed: 01/03/2023] Open
Abstract
Background: Malaria during pregnancy is a major health risk for both the mother and the foetus. Pregnancy has been shown to influence the pharmacokinetics of a number of different antimalarial drugs. This might lead to an under-exposure in these patients which could increase the risk of treatment failure and the development of drug resistance. The study aim was to evaluate the pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant patients using a population modelling approach. Methods: Twenty-four women in their second and third trimester of pregnancy and twenty-four paired non-pregnant women, all with uncomplicated P. falciparum malaria, were enrolled in this study. Treatment was a fixed-dose combination of oral artesunate and mefloquine once daily for three days. Frequent blood samples were collected and concentration-time data for artesunate and dihydroartemisinin were analysed simultaneously using nonlinear mixed-effects modelling. Results: Artesunate pharmacokinetics was best described by a transit-compartment absorption model followed by a one-compartment disposition model under the assumption of complete in vivo conversion of artesunate into dihydroartemisinin. Dihydroartemisinin pharmacokinetics was best described by a one-compartment disposition model with first-order elimination. Pregnant women had a 21% higher elimination clearance of dihydroartemisinin, compared to non-pregnant women, resulting in proportionally lower drug exposure. In addition, initial parasitaemia and liver status (alanine aminotransferase) were found to affect the relative bioavailability of artesunate. Conclusions: Results presented here show a substantially lower drug exposure to the antimalarial drug dihydroartemisinin during pregnancy after standard oral treatment of artesunate and mefloquine. This might result in an increased risk of treatment failure and drug resistance development, especially in low transmission settings where relative immunity is lower. Trial registration: ClinicalTrials.gov NCT00701961 (19/06/2008).
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Affiliation(s)
- Sofia Birgersson
- Department of Pharmacology, University of Gothenburg, Gothenburg, 405 30, Sweden
| | - Innocent Valea
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l’Ouest Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso
- Institut de Recherche en Sciences de la Sante´, Unite´ de Recherche Clinique de Nanoro, Nanoro, Burkina Faso
| | - Halidou Tinto
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l’Ouest Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso
- Institut de Recherche en Sciences de la Sante´, Unite´ de Recherche Clinique de Nanoro, Nanoro, Burkina Faso
| | - Maminata Traore-Coulibaly
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l’Ouest Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso
- Institut de Recherche en Sciences de la Sante´, Unite´ de Recherche Clinique de Nanoro, Nanoro, Burkina Faso
| | - Laeticia C. Toe
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l’Ouest Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso
- Department of Food Safety, Quality and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, B-9000, Belgium
| | - Richard M. Hoglund
- Mahidol-Oxford Tropical Medicine Resarch Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
- Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | | | - Stephen A. Ward
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | | | - Angela Abelö
- Department of Pharmacology, University of Gothenburg, Gothenburg, 405 30, Sweden
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Resarch Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
- Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
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12
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Birgersson S, Valea I, Tinto H, Traore-Coulibaly M, Toe LC, Hoglund RM, Van Geertruyden JP, Ward SA, D’Alessandro U, Abelö A, Tarning J. Population pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant women with uncomplicated Plasmodium falciparum malaria in Burkina Faso: an open label trial. Wellcome Open Res 2019. [DOI: 10.12688/wellcomeopenres.14849.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Malaria during pregnancy is a major health risk for both the mother and the foetus. Pregnancy has been shown to influence the pharmacokinetics of a number of different antimalarial drugs. This might lead to an under-exposure in these patients which could increase the risk of treatment failure and the development of drug resistance. The study aim was to evaluate the pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant patients using a population modelling approach. Methods: Twenty-four women in their second and third trimester of pregnancy and twenty-four paired non-pregnant women, all with uncomplicated P. falciparum malaria, were enrolled in this study. Treatment was a fixed-dose combination of oral artesunate and mefloquine once daily for three days. Frequent blood samples were collected and concentration-time data for artesunate and dihydroartemisinin were analysed simultaneously using nonlinear mixed-effects modelling. Results: Artesunate pharmacokinetics was best described by a transit-compartment absorption model followed by a one-compartment disposition model under the assumption of complete in vivo conversion of artesunate into dihydroartemisinin. Dihydroartemisinin pharmacokinetics was best described by a one-compartment disposition model with first-order elimination. Pregnant women had a 21% higher elimination clearance of dihydroartemisinin, compared to non-pregnant women, resulting in proportionally lower drug exposure. In addition, initial parasitaemia and liver status (alanine aminotransferase) were found to affect the relative bioavailability of artesunate. Conclusions: Results presented here show a substantially lower drug exposure to the antimalarial drug dihydroartemisinin during pregnancy after standard oral treatment of artesunate and mefloquine. This might result in an increased risk of treatment failure and drug resistance development, especially in low transmission settings where relative immunity is lower. Trial registration: ClinicalTrials.gov NCT00701961 (19/06/2008)
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13
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Saito M, Gilder ME, McGready R, Nosten F. Antimalarial drugs for treating and preventing malaria in pregnant and lactating women. Expert Opin Drug Saf 2018; 17:1129-1144. [PMID: 30351243 DOI: 10.1080/14740338.2018.1535593] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Malaria in pregnancy and postpartum cause maternal mortality and adverse fetal outcomes. Efficacious and safe antimalarials are needed to treat and prevent such serious consequences. However, because of the lack of evidence on fetal safety, quinine, an old and less efficacious drug has long been recommended for pregnant women. Uncertainty about safety in relation to breastfeeding leads to withholding of efficacious treatments postpartum or cessation of breastfeeding. Areas covered: A search identified literature on humans in three databases (MEDLINE, Embase and Global health) using pregnancy or lactation, and the names of antimalarial drugs as search terms. Adverse reactions to the mother, fetus or breastfed infant were summarized together with efficacies. Expert opinion: Artemisinins are more efficacious and well-tolerated than quinine in pregnancy. Furthermore, the risks of miscarriage, stillbirth or congenital abnormality were not higher in pregnancies exposed to artemisinin derivatives for treatment of malaria than in pregnancies exposed to quinine or in the comparable background population unexposed to any antimalarials, and this was true for treatment in any trimester. Assessment of safety and efficacy of antimalarials including dose optimization for pregnant women is incomplete. Resistance to sulfadoxine-pyrimethamine in Plasmodium falciparum and long unprotected intervals between intermittent treatment doses begs reconsideration of current preventative recommendations in pregnancy. Data remain limited on antimalarials during breastfeeding; while most first-line drugs appear safe, further research is needed.
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Affiliation(s)
- Makoto Saito
- a Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine , Mahidol University , Tak , Thailand.,b Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine , University of Oxford , Oxford , UK.,c WorldWide Antimalarial Resistance Network (WWARN) , Oxford , UK
| | - Mary Ellen Gilder
- a Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine , Mahidol University , Tak , Thailand
| | - Rose McGready
- a Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine , Mahidol University , Tak , Thailand.,b Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine , University of Oxford , Oxford , UK
| | - François Nosten
- a Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine , Mahidol University , Tak , Thailand.,b Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine , University of Oxford , Oxford , UK
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14
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Population Pharmacokinetics of the Antimalarial Amodiaquine: a Pooled Analysis To Optimize Dosing. Antimicrob Agents Chemother 2018; 62:AAC.02193-17. [PMID: 30038039 PMCID: PMC6153844 DOI: 10.1128/aac.02193-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 06/22/2018] [Indexed: 01/16/2023] Open
Abstract
Amodiaquine plus artesunate is the recommended antimalarial treatment in many countries where malaria is endemic. However, pediatric doses are largely based on a linear extrapolation from adult doses. Amodiaquine plus artesunate is the recommended antimalarial treatment in many countries where malaria is endemic. However, pediatric doses are largely based on a linear extrapolation from adult doses. We pooled data from previously published studies on the pharmacokinetics of amodiaquine, to optimize the dose across all age groups. Adults and children with uncomplicated malaria received daily weight-based doses of amodiaquine or artesunate-amodiaquine over 3 days. Plasma concentration-time profiles for both the parent drug and the metabolite were characterized using nonlinear mixed-effects modeling. Amodiaquine pharmacokinetics were adequately described by a two-compartment disposition model, with first-order elimination leading to the formation of desethylamodiaquine, which was best described by a three-compartment disposition model. Body size and age were the main covariates affecting amodiaquine clearance. After adjusting for the effect of weight, clearance rates for amodiaquine and desethylamodiaquine reached 50% of adult maturation at 2.8 months (95% confidence interval [CI], 1.5 to 3.7 months) and 3.9 months (95% CI, 2.6 to 5.3 months) after birth, assuming that the baby was born at term. Bioavailability was 22.4% (95% CI, 15.6 to 31.9%) lower at the start of treatment than during convalescence, which suggests a malaria disease effect. Neither the drug formulation nor the hemoglobin concentration had an effect on any pharmacokinetic parameters. Results from simulations showed that current manufacturer dosing recommendations resulted in low desethylamodiaquine exposure in patients weighing 8 kg, 15 to 17 kg, 33 to 35 kg, and >62 kg compared to that in a typical 50-kg patient. We propose possible optimized dosing regimens to achieve similar drug exposures among all age groups, which require further validation.
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15
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Hecht M, Veigure R, Couchman L, S Barker CI, Standing JF, Takkis K, Evard H, Johnston A, Herodes K, Leito I, Kipper K. Utilization of data below the analytical limit of quantitation in pharmacokinetic analysis and modeling: promoting interdisciplinary debate. Bioanalysis 2018; 10:1229-1248. [PMID: 30033744 DOI: 10.4155/bio-2018-0078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Traditionally, bioanalytical laboratories do not report actual concentrations for samples with results below the LOQ (BLQ) in pharmacokinetic studies. BLQ values are outside the method calibration range established during validation and no data are available to support the reliability of these values. However, ignoring BLQ data can contribute to bias and imprecision in model-based pharmacokinetic analyses. From this perspective, routine use of BLQ data would be advantageous. We would like to initiate an interdisciplinary debate on this important topic by summarizing the current concepts and use of BLQ data by regulators, pharmacometricians and bioanalysts. Through introducing the limit of detection and evaluating its variability, BLQ data could be released and utilized appropriately for pharmacokinetic research.
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Affiliation(s)
- Max Hecht
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Rūta Veigure
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Lewis Couchman
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Charlotte I S Barker
- Paediatric Infectious Diseases Research Group, Institute for Infection & Immunity, St George's University of London, London, SW17 0RE, UK
- Inflammation, Infection & Rheumatology Section, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
- Paediatric Infectious Diseases Unit, St George's University Hospitals NHS Foundation Trust, London, SW17 0RE, UK
| | - Joseph F Standing
- Paediatric Infectious Diseases Research Group, Institute for Infection & Immunity, St George's University of London, London, SW17 0RE, UK
- Inflammation, Infection & Rheumatology Section, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
| | - Kalev Takkis
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Hanno Evard
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Atholl Johnston
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
- Clinical Pharmacology, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Koit Herodes
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Ivo Leito
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Karin Kipper
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
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16
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D'Alessandro U, Hill J, Tarning J, Pell C, Webster J, Gutman J, Sevene E. Treatment of uncomplicated and severe malaria during pregnancy. THE LANCET. INFECTIOUS DISEASES 2018; 18:e133-e146. [PMID: 29395998 DOI: 10.1016/s1473-3099(18)30065-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 07/19/2017] [Accepted: 10/13/2017] [Indexed: 12/13/2022]
Abstract
Over the past 10 years, the available evidence on the treatment of malaria during pregnancy has increased substantially. Owing to their relative ease of use, good sensitivity and specificity, histidine rich protein 2 based rapid diagnostic tests are appropriate for symptomatic pregnant women; however, such tests are less appropriate for systematic screening because they will not detect an important proportion of infections among asymptomatic women. The effect of pregnancy on the pharmacokinetics of antimalarial drugs varies greatly between studies and class of antimalarial drugs, emphasising the need for prospective studies in pregnant and non-pregnant women. For the treatment of malaria during the first trimester, international guidelines are being reviewed by WHO. For the second and third trimester of pregnancy, results from several trials have confirmed that artemisinin-based combination treatments are safe and efficacious, although tolerability and efficacy might vary by treatment. It is now essential to translate such evidence into policies and clinical practice that benefit pregnant women in countries where malaria is endemic. Access to parasitological diagnosis or appropriate antimalarial treatment remains low in many countries and regions. Therefore, there is a pressing need for research to identify quality improvement interventions targeting pregnant women and health providers. In addition, efficient and practical systems for pharmacovigilance are needed to further expand knowledge on the safety of antimalarial drugs, particularly in the first trimester of pregnancy.
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Affiliation(s)
- Umberto D'Alessandro
- Medical Research Council Unit, Banjul, The Gambia; London School of Hygiene & Tropical Medicine, London, UK.
| | - Jenny Hill
- Liverpool School of Tropical Medicine, Liverpool, 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
| | - Christopher Pell
- Centre for Social Science and Global Health, University of Amsterdam, Amsterdam, Netherlands; Amsterdam Institute for Global Health and Development, Amsterdam, Netherlands
| | - Jayne Webster
- London School of Hygiene & Tropical Medicine, London, UK
| | - Julie Gutman
- Malaria Branch, US Centers for Diseases Control and Prevention, Atlanta, GA, USA
| | - Esperanca Sevene
- Manhiça Health Research Center (CISM), Manhiça, Mozambique; Faculty of Medicine, Eduardo Mondlane University, Maputo, Mozambique
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17
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Abstract
Increasing antimalarial drug resistance once again threatens effective antimalarial drug treatment, malaria control, and elimination. Artemisinin combination therapies (ACTs) are first-line treatment for uncomplicated falciparum malaria in all endemic countries, yet partial resistance to artemisinins has emerged in the Greater Mekong Subregion. Concomitant emergence of partner drug resistance is now causing high ACT treatment failure rates in several areas. Genetic markers for artemisinin resistance and several of the partner drugs have been established, greatly facilitating surveillance. Single point mutations in the gene coding for the Kelch propeller domain of the K13 protein strongly correlate with artemisinin resistance. Novel regimens and strategies using existing antimalarial drugs will be needed until novel compounds can be deployed. Elimination of artemisinin resistance will imply elimination of all falciparum malaria from the same areas. In vivax malaria, chloroquine resistance is an increasing problem.
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Affiliation(s)
- Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur in Cambodia, Phnom Penh 12201, Cambodia
| | - Arjen Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 73170, Thailand
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18
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Moore BR, Salman S, Davis TME. Treatment regimens for pregnant women with falciparum malaria. Expert Rev Anti Infect Ther 2016; 14:691-704. [PMID: 27322015 DOI: 10.1080/14787210.2016.1202758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION With increasing parasite drug resistance, the WHO has updated treatment recommendations for falciparum malaria including in pregnancy. This review assesses the evidence for choice of treatment for pregnant women. AREAS COVERED Relevant studies, primarily those published since 2010, were identified from reference databases and were used to identify secondary data sources. Expert commentary: WHO recommends use of intravenous artesunate for severe malaria, quinine-clindamycin for uncomplicated malaria in first trimester, and artemisinin combination therapy for uncomplicated malaria in second/third trimesters. Because fear of adverse outcomes has often excluded pregnant women from conventional drug development, available data for novel therapies are usually based on preclinical studies and cases of inadvertent exposure. Changes in antimalarial drug disposition in pregnancy have been observed but are yet to be translated into specific treatment recommendations. Such targeted regimens may become important as parasite resistance demands that drug exposure is optimized.
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Affiliation(s)
- Brioni R Moore
- a Fiona Stanley Hospital Unit, School of Medicine and Pharmacology , University of Western Australia , Perth , Australia.,b School of Pharmacy , Curtin University , Perth , Australia
| | - Sam Salman
- c Linear Clinical Research Limited, QEII Medical Centre , Nedlands , Australia.,d Fremantle Hospital Unit, School of Medicine and Pharmacology , University of Western Australia , Fremantle , Australia
| | - Timothy M E Davis
- d Fremantle Hospital Unit, School of Medicine and Pharmacology , University of Western Australia , Fremantle , Australia
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19
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Sambol NC, Tappero JW, Arinaitwe E, Parikh S. Rethinking Dosing Regimen Selection of Piperaquine for Malaria Chemoprevention: A Simulation Study. PLoS One 2016; 11:e0154623. [PMID: 27182702 PMCID: PMC4868321 DOI: 10.1371/journal.pone.0154623] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/17/2016] [Indexed: 11/29/2022] Open
Abstract
Background The combination of short-acting dihydroartemisinin and long-acting piperaquine (DP) is among the first-line therapies for the treatment of uncomplicated Plasmodium falciparum malaria. Population pharmacokinetic models of piperaquine (PQ) based on data from acute treatment of young children can be used to predict exposure profiles of piperaquine under different DP chemoprevention regimens. The purpose of our study was to make such predictions in young children. Methods Based on a prior population pharmacokinetic model of PQ in young Ugandan children, we simulated capillary plasma concentration-time profiles (including their variability) of candidate chemoprevention regimens for a reference population of 1–2 year olds weighing at least 11 kg. Candidate regimens that were tested included monthly administration of standard therapeutic doses, bimonthly dosing, and weekly dosing (with and without a loading dose). Results Once daily doses of 320 mg for three days (960 mg total) at the beginning of each month are predicted to achieve an average steady-state trough capillary piperaquine concentration of 35 ng/mL, with 60% achieving a level of 30 ng/mL or higher. In contrast, weekly dosing of 320 mg (i.e., 33% higher amount per month) is predicted to approximately double the average steady-state trough concentration, increase the percent of children predicted to achieve 30 ng/mL or higher (94%), while at the same time lowering peak concentrations. Exposure at steady-state, reached at approximately 3 months of multiple dosing, is expected to be approximately 2-fold higher than exposure following initial dosing, due to accumulation. A loading dose improves early exposure, thereby reducing the risk of breakthrough infections at the initiation of chemoprevention. Conclusions Once weekly chemoprevention of DP predicts favourable exposures with respect to both trough and peak concentrations. These predictions need to be verified, as well as safety evaluated, in field-based clinical studies of young children. Simulations based on prior knowledge provide a systematic information-driven approach to evaluate candidate DP chemopreventive regimens for future trial designs.
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Affiliation(s)
- Nancy C. Sambol
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, United States of America
| | - Jordan W. Tappero
- Centers for Global Health, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America
| | | | - Sunil Parikh
- Yale School of Public Health, New Haven, Connecticut, United States of America
- * E-mail:
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20
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Tasnif Y, Morado J, Hebert MF. Pregnancy-related pharmacokinetic changes. Clin Pharmacol Ther 2016; 100:53-62. [PMID: 27082931 DOI: 10.1002/cpt.382] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/12/2016] [Indexed: 01/10/2023]
Abstract
The pharmacokinetics of many drugs are altered by pregnancy. Drug distribution and protein binding are changed by pregnancy. While some drug metabolizing enzymes have an apparent increase in activity, others have an apparent decrease in activity. Not only is drug metabolism affected by pregnancy, but renal filtration is also increased. In addition, pregnancy alters the apparent activities of multiple drug transporters resulting in changes in the net renal secretion of drugs.
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Affiliation(s)
- Y Tasnif
- Cooperative Pharmacy Program, University of Texas, Rio Grande Valley TX and Renaissance Transplant Institute, Doctors Hospital at Renaissance, Edinburg, Texas, USA
| | - J Morado
- College of Pharmacy, University of Texas at Austin, Austin, Texas, USA
| | - M F Hebert
- Departments of Pharmacy and Obstetrics & Gynecology, University of Washington, Seattle, WA, USA
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21
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González R, Sevene E, Jagoe G, Slutsker L, Menéndez C. A Public Health Paradox: The Women Most Vulnerable to Malaria Are the Least Protected. PLoS Med 2016; 13:e1002014. [PMID: 27139032 PMCID: PMC4854455 DOI: 10.1371/journal.pmed.1002014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Raquel Gonzalez and colleagues highlight an urgent need to evaluate antimalarials that can be safely administered to HIV-infected pregnant women on antiretroviral treatment and cotrimoxazole prophylaxis.
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Affiliation(s)
- Raquel González
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic- Universitat de Barcelona, Barcelona, Spain
- Manhiça Health Research Center (CISM), Manhiça, Mozambique
- * E-mail:
| | - Esperança Sevene
- Manhiça Health Research Center (CISM), Manhiça, Mozambique
- Eduardo Mondlane University, Faculty of Medicine, Maputo, Mozambique
| | - George Jagoe
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Laurence Slutsker
- Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Clara Menéndez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic- Universitat de Barcelona, Barcelona, Spain
- Manhiça Health Research Center (CISM), Manhiça, Mozambique
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22
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Burger RJ, Visser BJ, Grobusch MP, van Vugt M. The influence of pregnancy on the pharmacokinetic properties of artemisinin combination therapy (ACT): a systematic review. Malar J 2016; 15:99. [PMID: 26891915 PMCID: PMC4757991 DOI: 10.1186/s12936-016-1160-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 02/10/2016] [Indexed: 11/10/2022] Open
Abstract
Background Pregnancy has been reported to alter the pharmacokinetic properties of anti-malarial drugs, including the different components of artemisinin-based combination therapy (ACT). However, small sample sizes make it difficult to draw strong conclusions based on individual pharmacokinetic studies. The aim of this review is to summarize the evidence of the influence of pregnancy on the pharmacokinetic properties of different artemisinin-based combinations. Methods A PROSPERO-registered systematic review to identify clinical trials that investigated the influence of pregnancy on the pharmacokinetic properties of different forms of ACT was conducted, following PRISMA guidelines. Without language restrictions, Medline/PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, LILACS, Biosis Previews and the African Index Medicus were searched for studies published up to November 2015. The following components of ACT that are currently recommend by the World Health Organization as first-line treatment of malaria in pregnancy were reviewed: artemisinin, artesunate, dihydroartemisinin, lumefantrine, amodiaquine, mefloquine, sulfadoxine, pyrimethamine, piperaquine, atovaquone and proguanil. Results The literature search identified 121 reports, 27 original studies were included. 829 pregnant women were included in the analysis. Comparison of the available studies showed lower maximum concentrations (Cmax) and exposure (AUC) of dihydroartemisinin, the active metabolite of all artemisinin derivatives, after oral administration of artemether, artesunate and dihydroartemisinin in pregnant women. Low day 7 concentrations were commonly seen in lumefantrine studies, indicating a low exposure and possibly reduced efficacy. The influence of pregnancy on amodiaquine and piperaquine seemed not to be clinically relevant. Sulfadoxine plasma concentration was significantly reduced and clearance rates were higher in pregnancy, while pyrimethamine and mefloquine need more research as no general conclusion can be drawn based on the available evidence. For atovaquone, the available data showed a lower maximum concentration and exposure. Finally, the maximum concentration of cycloguanil, the active metabolite of proguanil, was significantly lower, possibly compromising the efficacy. Conclusion These findings suggest that reassessment of the dose of the artemisinin derivate and some components of ACT are necessary to ensure the highest possible efficacy of malaria treatment in pregnant women. However, for most components of ACT, data were insufficient and extensive research with larger sample sizes will be necessary to identify the exact influences of pregnancy on the pharmacokinetic properties of different artemisinin-based combinations. In addition, different clinical studies used diverse study designs with various reported relevant outcomes. Future pharmacokinetic studies could benefit from more uniform designs, in order to increase quality, robustness and effectiveness. Study registration: CRD42015023756 (PROSPERO) Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1160-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Renée J Burger
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
| | - Benjamin J Visser
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Centre de Recherches de Médicales de Lambaréné (CERMEL), Albert Schweitzer Hospital, Lambaréné, Gabon.
| | - Martin P Grobusch
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands. .,Centre de Recherches de Médicales de Lambaréné (CERMEL), Albert Schweitzer Hospital, Lambaréné, Gabon.
| | - Michèle van Vugt
- Division of Internal Medicine, Department of Infectious Diseases, Academic Medical Center, Center of Tropical Medicine and Travel Medicine, University of Amsterdam, Meibergdreef 9, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
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Shah RR, Gaedigk A, LLerena A, Eichelbaum M, Stingl J, Smith RL. CYP450 genotype and pharmacogenetic association studies: a critical appraisal. Pharmacogenomics 2016; 17:259-75. [DOI: 10.2217/pgs.15.172] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Despite strong pharmacological support, association studies using genotype-predicted phenotype as a variable have yielded conflicting or inconclusive evidence to promote personalized pharmacotherapy. Unless the patient is a genotypic poor metabolizer, imputation of patient's metabolic capacity (or metabolic phenotype), a major factor in drug exposure-related clinical response, is a complex and highly challenging task because of limited number of alleles interrogated, population-specific differences in allele frequencies, allele-specific substrate-selectivity and importantly, phenoconversion mediated by co-medications and inflammatory co-morbidities that modulate the functional activity of drug metabolizing enzymes. Furthermore, metabolic phenotype and clinical outcomes are not binary functions; there is large intragenotypic and intraindividual variability. Therefore, the ability of association studies to identify relationships between genotype and clinical outcomes can be greatly enhanced by determining phenotype measures of study participants and/or by therapeutic drug monitoring to correlate drug concentrations with genotype and actual metabolic phenotype. To facilitate improved analysis and reporting of association studies, we propose acronyms with the prefixes ‘g’ (genotype-predicted phenotype) and ‘m’ (measured metabolic phenotype) to better describe this important variable of the study subjects. Inclusion of actually measured metabolic phenotype, and when appropriate therapeutic drug monitoring, promises to reveal relationships that may not be detected by using genotype alone as the variable.
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Affiliation(s)
| | - Andrea Gaedigk
- Clinical Pharmacology, Toxicology &, Therapeutic Innovation, Children's Mercy-Kansas City, 2401 Gillham Rd, Kansas City, MO 64108, USA
- School of Medicine, University of Missouri-Kansas City, MO, USA
| | - Adrián LLerena
- CICAB Clinical Research Centre, Extremadura University Hospital & Medical School, Badajoz, Spain
| | - Michel Eichelbaum
- Dr. Margarete Fischer-Bosch – Institut für Klinische Pharmakologie, 70376 Stuttgart Auerbachstr., 112 Germany
| | - Julia Stingl
- Centre for Translational Medicine, University of Bonn Medical School, Bonn, Germany
| | - Robert L Smith
- Department of Surgery & Cancer, Faculty of Medicine, Imperial College, South Kensington Campus, London, UK
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Artemether-Lumefantrine Pharmacokinetics and Clinical Response Are Minimally Altered in Pregnant Ugandan Women Treated for Uncomplicated Falciparum Malaria. Antimicrob Agents Chemother 2015; 60:1274-82. [PMID: 26666942 PMCID: PMC4775973 DOI: 10.1128/aac.01605-15] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 11/13/2015] [Indexed: 12/03/2022] Open
Abstract
Artemether-lumefantrine is a first-line regimen for the treatment of uncomplicated malaria during the second and third trimesters of pregnancy. Previous studies have reported changes in the pharmacokinetics and clinical outcomes following treatment with artemether-lumefantrine in pregnant women compared to nonpregnant adults; however, the results are inconclusive. We conducted a study in rural Uganda to compare the pharmacokinetics of artemether-lumefantrine and the treatment responses between 30 pregnant women and 30 nonpregnant adults with uncomplicated Plasmodium falciparum malaria. All participants were uninfected with HIV, treated with a six-dose regimen of artemether-lumefantrine, and monitored clinically for 42 days. The pharmacokinetics of artemether, its metabolite dihydroartemisinin, and lumefantrine were evaluated for 21 days following treatment. We found no significant differences in the overall pharmacokinetics of artemether, dihydroartemisinin, or lumefantrine in a direct comparison of pregnant women to nonpregnant adults, except for a statistically significant but small difference in the terminal elimination half-lives of both dihydroartemisinin and lumefantrine. There were seven PCR-confirmed reinfections (5 pregnant and 2 nonpregnant participants). The observation of a shorter terminal half-life for lumefantrine may have contributed to a higher frequency of reinfection or a shorter posttreatment prophylactic period in pregnant women than in nonpregnant adults. While the comparable overall pharmacokinetic exposure is reassuring, studies are needed to further optimize antimalarial efficacy in pregnant women, particularly in high-transmission settings and because of emerging drug resistance. (This study is registered at ClinicalTrials.gov under registration no. NCT01717885.)
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Srinivas NR. Is there a differential conversion of artesunate to dihydroartemisinin in pregnant vs. post-partum patients with malaria after oral artesunate dosing? Br J Clin Pharmacol 2015; 81:389-90. [PMID: 26521664 DOI: 10.1111/bcp.12809] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 10/15/2015] [Accepted: 10/20/2015] [Indexed: 11/29/2022] Open
Affiliation(s)
- Nuggehally R Srinivas
- Suramus Bio, Drug Development, J.P. Nagar I Phase, Bangalore, 560078, Karnataka, India
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