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Moore BR, Davis TME. Pharmacotherapy for the prevention of malaria in pregnant women: currently available drugs and challenges. Expert Opin Pharmacother 2018; 19:1779-1796. [PMID: 30289730 DOI: 10.1080/14656566.2018.1526923] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Malaria in pregnancy continues to be a significant public health burden globally, with over 100 million women at risk each year. Sulfadoxine-pyrimethamine (SP) is the only antimalarial recommended for intermittent preventive therapy in pregnancy (IPTp) but increasing parasite resistance threatens its viability. There are few other available antimalarial therapies that currently have sufficient evidence of tolerability, safety, and efficacy to replace SP. AREAS COVERED Novel antimalarial combinations are under investigation for potential use as chemoprophylaxis and in IPTp regimens. The present review summarizes currently available therapies, emerging candidate combination therapies, and the potential challenges to integrating these into mainstream policy. EXPERT OPINION Alternative drugs or combination therapies to SP for IPTp are desperately required. Dihydroartemisinin-piperaquine and azithromycin-based combinations are showing great promise as potential candidates for IPTp but pharmacokinetic data suggest that dose modification may be required to ensure adequate prophylactic efficacy. If a suitable candidate regimen is not identified in the near future, the success of chemopreventive strategies such as IPTp may be in jeopardy.
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Affiliation(s)
- Brioni R Moore
- a School of Pharmacy and Biomedical Sciences , Curtin University , Bentley , Western Australia , Australia.,b Medical School , University of Western Australia , Crawley , Western Australia , Australia
| | - Timothy M E Davis
- b Medical School , University of Western Australia , Crawley , Western Australia , Australia
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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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Abstract
Severe malaria in pregnancy is a large contributor to maternal morbidity and mortality. Intravenous quinine has traditionally been the treatment drug of choice for severe malaria in pregnancy. However, recent randomized clinical trials (RCTs) indicate that intravenous artesunate is more efficacious for treating severe malaria, resulting in changes to the World Health Organization (WHO) treatment guidelines. Artemisinins, including artesunate, are embryo-lethal in animal studies and there is limited experience with their use in the first trimester. This review summarizes the current literature supporting 2010 WHO treatment guidelines for severe malaria in pregnancy and the efficacy, pharmacokinetics, and adverse event data for currently used antimalarials available for severe malaria in pregnancy. We identified ten studies on the treatment of severe malaria in pregnancy that reported clinical outcomes. In two studies comparing intravenous quinine with intravenous artesunate, intravenous artesunate was more efficacious and safe for use in pregnant women. No studies detected an increased risk of miscarriage, stillbirth, or congenital anomalies associated with first trimester exposure to artesunate. Although the WHO recommends using either quinine or artesunate for the treatment of severe malaria in first trimester pregnancies, our findings suggest that artesunate should be the preferred treatment option for severe malaria in all trimesters.
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Tagbor H, Mahama RP, Antwi G. Antimalarial drug combinations for treating uncomplicated malaria in pregnancy. Hippokratia 2015. [DOI: 10.1002/14651858.cd011832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Harry Tagbor
- Kwame Nkrumah University of Science & Technology; School of Public Health, College of Health Sciences; PO Box UP861 KNUST Kumasi Ghana
- Centre for Global Health Research; Kumasi Ghana
| | | | - Gifty Antwi
- Centre for Global Health Research; Kumasi Ghana
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Population pharmacokinetic and pharmacodynamic modeling of amodiaquine and desethylamodiaquine in women with Plasmodium vivax malaria during and after pregnancy. Antimicrob Agents Chemother 2012; 56:5764-73. [PMID: 22926572 DOI: 10.1128/aac.01242-12] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Amodiaquine is effective for the treatment of Plasmodium vivax malaria, but there is little information on the pharmacokinetic and pharmacodynamic properties of amodiaquine in pregnant women with malaria. This study evaluated the population pharmacokinetic and pharmacodynamic properties of amodiaquine and its biologically active metabolite, desethylamodiaquine, in pregnant women with P. vivax infection and again after delivery. Twenty-seven pregnant women infected with P. vivax malaria on the Thai-Myanmar border were treated with amodiaquine monotherapy (10 mg/kg/day) once daily for 3 days. Nineteen women, with and without P. vivax infections, returned to receive the same amodiaquine dose postpartum. Nonlinear mixed-effects modeling was used to evaluate the population pharmacokinetic and pharmacodynamic properties of amodiaquine and desethylamodiaquine. Amodiaquine plasma concentrations were described accurately by lagged first-order absorption with a two-compartment disposition model followed by a three-compartment disposition of desethylamodiaquine under the assumption of complete in vivo conversion. Body weight was implemented as an allometric function on all clearance and volume parameters. Amodiaquine clearance decreased linearly with age, and absorption lag time was reduced in pregnant patients. Recurrent malaria infections in pregnant women were modeled with a time-to-event model consisting of a constant-hazard function with an inhibitory effect of desethylamodiaquine. Amodiaquine treatment reduced the risk of recurrent infections from 22.2% to 7.4% at day 35. In conclusion, pregnancy did not have a clinically relevant impact on the pharmacokinetic properties of amodiaquine or desethylamodiaquine. No dose adjustments are required in pregnancy.
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Wilby KJ, Ensom MHH. Pharmacokinetics of antimalarials in pregnancy: a systematic review. Clin Pharmacokinet 2012; 50:705-23. [PMID: 21973268 DOI: 10.2165/11594550-000000000-00000] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Malaria is a serious parasitic infection, which affects millions of people worldwide. As pregnancy has been shown to alter the pharmacokinetics of many medications, the efficacy and safety of antimalarial drug regimens may be compromised in pregnant women. The objective of this review is to systematically review published literature on the pharmacokinetics of antimalarial agents in pregnant women. A search of MEDLINE (1948-May 2011), EMBASE (1980-May 2011), International Pharmaceutical Abstracts (1970-May 2011), Google and Google Scholar was conducted for articles describing the pharmacokinetics of antimalarials in pregnancy (and supplemented by a bibliographic review of all relevant articles); all identified studies were summarized and evaluated according to the level of evidence, based on the classification system developed by the US Preventive Services Task Force. Identified articles were included in the review if the study had at least one group that reported at least one pharmacokinetic parameter of interest in pregnant women. Articles were excluded from the review if no pharmacokinetic information was reported or if both pregnant and non-pregnant women were analysed within the same group. For quinine and its metabolites, there were three articles (one level II-1 and two level III); for artemisinin compounds, two articles (both level III); for lumefantrine, two articles (both level III); for atovaquone, two articles (both level III); for proguanil, three articles (one level II-1 and two level III); for sulfadoxine, three articles (all level II-1); for pyrimethamine, three articles (all level II-1); for chloroquine and its metabolite, four articles (three level II-1 and one level II-3); for mefloquine, two articles (one level II-1 and one level III); and for azithromycin, two articles (one level II-1 and one level III). Although comparative trials were identified, most of these studies were descriptive and classified as level III evidence. The main findings showed that pharmacokinetic parameters are commonly altered in pregnancy for the majority of recommended agents. Importantly, first-line regimens of artemisinin-based compounds, lumefantrine, chloroquine and pyrimethamine/sulfadoxine may undergo significant changes that could decrease therapeutic efficacy. These changes are usually due to increases in the apparent oral clearance and volume of distribution that commonly occur in pregnant women, and may result in decreased exposure and increased therapeutic failure. In order to assess the clinical implications of these changes and to provide safe and effective dosage regimens, there is an immediate need for dose-optimization studies of all recommended first- and second-line agents used in pregnant women with malaria.
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Affiliation(s)
- Kyle J Wilby
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
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Pharmacokinetics of amodiaquine and desethylamodiaquine in pregnant and postpartum women with Plasmodium vivax malaria. Antimicrob Agents Chemother 2011; 55:4338-42. [PMID: 21709098 DOI: 10.1128/aac.00154-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to study the pharmacokinetic properties of amodiaquine and desethylamodiaquine during pregnancy, 24 pregnant women in the second and third trimesters of pregnancy and with Plasmodium vivax malaria were treated with amodiaquine (10 mg/kg of body weight/day) for 3 days. The same women were studied again at 3 months postpartum. Plasma was analyzed for amodiaquine and desethylamodiaquine by use of a liquid chromatography-tandem mass spectrometry method. Individual concentration-time data were evaluated using noncompartmental analysis. There were no clinically relevant differences in the pharmacokinetics of amodiaquine and desethylamodiaquine between pregnant (n = 24) and postpartum (n = 18) women. The results suggest that the current amodiaquine dosing regimen is adequate for the treatment of P. vivax infections during pregnancy.
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Sevene E, González R, Menéndez C. Current knowledge and challenges of antimalarial drugs for treatment and prevention in pregnancy. Expert Opin Pharmacother 2010; 11:1277-93. [PMID: 20408744 DOI: 10.1517/14656561003733599] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
IMPORTANCE OF THE FIELD Malaria infection during pregnancy is a major public health problem worldwide, with 50 million pregnancies exposed to the infection every year. Approximately 25,000 maternal deaths and between 75,000 and 200,000 infant deaths could be prevented each year by effective malaria control in pregnancy. Antimalarial drug treatment and prevention has been hampered by the appearance of drug resistance, which has been a particular problem in pregnancy due to the inherent safety issues. AREAS COVERED IN THIS REVIEW New antimalarial drugs and combinations are being studied but there is not yet sufficient information on their efficacy or, more importantly, on their safety in pregnancy. This article provides an overview of the relevance of the topic and reviews the current antimalarial drugs recommended for pregnancy, as well as the guidelines for both treatment and prevention in women living in endemic areas and for travellers. WHAT THE READER WILL GAIN Updated information on the drugs currently used for malaria treatment and prevention in pregnancy, including new drugs under development, is provided. The gaps on efficacy and safety information for use during pregnancy are also discussed. TAKE HOME MESSAGE Prevention and case management of malaria during pregnancy is based on risk-benefit criteria and poses one of the greatest challenges to current malaria control.
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Affiliation(s)
- Esperança Sevene
- Eduardo Mondlane University, Faculty of Medicine, CIMed, Maputo, Mozambique.
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Investigation of reproductive toxicity of piperaquine in mice. Reprod Toxicol 2010; 29:206-13. [DOI: 10.1016/j.reprotox.2009.10.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 10/19/2009] [Accepted: 10/28/2009] [Indexed: 11/20/2022]
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Mutabingwa TK, Muze K, Ord R, Briceño M, Greenwood BM, Drakeley C, Whitty CJM. Randomized trial of artesunate+amodiaquine, sulfadoxine-pyrimethamine+amodiaquine, chlorproguanal-dapsone and SP for malaria in pregnancy in Tanzania. PLoS One 2009; 4:e5138. [PMID: 19352498 PMCID: PMC2662423 DOI: 10.1371/journal.pone.0005138] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2008] [Accepted: 03/13/2009] [Indexed: 11/25/2022] Open
Abstract
Background Malaria in pregnancy is serious, and drug resistance in Africa is spreading. Drugs have greater risks in pregnancy and determining the safety and efficacy of drugs in pregnancy is therefore a priority. This study set out to determine the efficacy and safety of several antimalarial drugs and combinations in pregnant women with uncomplicated malaria. Methods Pregnant women with non-severe, slide proven, falciparum malaria were randomised to one of 4 regimes: sulfadoxine-pyrimethamine [SP]; chlorproguanil-dapsone [CD]; SP+amodiaquine [SP+AQ] or amodiaquine+artesunate [AQ+AS]. Randomisation was on a 1∶2∶2∶2 ratio. Women were admitted for treatment, and followed at days 7, 14, 21, 28 after the start of treatment, at delivery and 6 weeks after delivery to determine adverse events, clinical and parasitological outcomes. Primary outcome was parasitological failure by day 28. Results 1433 pregnant women were screened, of whom 272 met entry criteria and were randomised; 28 to SP, 81 to CD, 80 to SP+AQ and 83 to AQ+AS. Follow-up to day 28 post treatment was 251/272 (92%), and to 6 weeks following delivery 91%. By day 28 parasitological failure rates were 4/26 (15%, 95%CI 4–35) in the SP, 18/77 (23%, 95%CI 14–34) in the CD, 1/73 (1% 95%CI 7–0.001) in the SP+AQ and 7/75 (9% 95%CI 4–18) in the AQ+AS arms respectively. After correction by molecular markers for reinfection the parasitological failure rates at day 28 were 18% for CD, 1% for SP+AQ and 4.5% for AQ+AS. There were two maternal deaths during the trial. There was no apparent excess of stillbirths or adverse birth outcomes in any arm. Parasitological responses were strikingly better in pregnant women than in children treated with the same drugs at this site. Conclusions Failure rates with monotherapy were unacceptably high. The two combinations tested were efficacious and appeared safe. It should not be assumed that efficacy in pregnancy is the same as in children. Trial Registration ClinicalTrials.gov NCT00146731
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Affiliation(s)
- Theonest K Mutabingwa
- Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom.
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Stokes E, Dumbaya I, Owens S, Brabin L. The right to remain silent: a qualitative study of the medical and social ramifications of pregnancy disclosure for Gambian women. BJOG 2009; 115:1641-7; discussion 1647. [PMID: 19035940 DOI: 10.1111/j.1471-0528.2008.01950.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Control of infectious diseases in developing countries often requires using drugs that are contraindicated during pregnancy. Avoiding inadvertent exposure to drugs involves women (a) recognising pregnancy early, (b) disclosing the pregnancy to health workers and (c) using medicines in an informed manner. We explored these factors to inform and improve the process by which health workers provide care and treatment to pregnant women. DESIGN Qualitative study. SETTING The Gambia. POPULATION Rural women and men. METHODS We conducted 41 interviews and 16 focus group discussions with women, adolescents, men and traditional birth attendants (TBAs). MAIN OUTCOME MEASURE Pregnancy disclosure. RESULTS Most women recognised early signs and symptoms of pregnancy and believed other people could easily do so. To avoid gossip, women hid their pregnancies and delayed antenatal care, even though husbands and TBAs insisted on attendance. Women acutely ill in early pregnancy hoped health workers would recognise pregnancy without explicit disclosure. Women said that they knew, and sought to avoid, some contraindicated drugs, but their knowledge was rudimentary. Health workers stressed the benefits, not the risks of prescribed drugs. CONCLUSIONS Despite public health and clinical benefits of preventing and treating pregnancy infections, women were ill informed and pressurised into taking drugs. These ethical issues should be more widely addressed.
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Affiliation(s)
- E Stokes
- Academic Unit of Obstetrics and Gynaecology, University of Manchester, Manchester, UK
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High resistance of Plasmodium falciparum to sulphadoxine/pyrimethamine in northern Tanzania and the emergence of dhps resistance mutation at Codon 581. PLoS One 2009; 4:e4569. [PMID: 19238219 PMCID: PMC2644264 DOI: 10.1371/journal.pone.0004569] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Accepted: 12/12/2008] [Indexed: 12/04/2022] Open
Abstract
Background Sulphadoxine-pyrimethamine (SP) a widely used treatment for uncomplicated malaria and recommended for intermittent preventive treatment of malaria in pregnancy, is being investigated for intermittent preventive treatment of malaria in infants (IPTi). High levels of drug resistance to SP have been reported from north-eastern Tanzania associated with mutations in parasite genes. This study compared the in vivo efficacy of SP in symptomatic 6–59 month children with uncomplicated malaria and in asymptomatic 2–10 month old infants. Methodology and Principal Findings An open label single arm (SP) standard 28 day in vivo WHO antimalarial efficacy protocol was used in 6 to 59 months old symptomatic children and a modified protocol used in 2 to 10 months old asymptomatic infants. Enrolment was stopped early (87 in the symptomatic and 25 in the asymptomatic studies) due to the high failure rate. Molecular markers were examined for recrudescence, re-infection and markers of drug resistance and a review of literature of studies looking for the 581G dhps mutation was carried out. In symptomatic children PCR-corrected early treatment failure was 38.8% (95% CI 26.8–50.8) and total failures by day 28 were 82.2% (95% CI 72.5–92.0). There was no significant difference in treatment failures between asymptomatic and symptomatic children. 96% of samples carried parasites with mutations at codons 51, 59 and 108 in the dhfr gene and 63% carried a double mutation at codons 437 and 540. 55% carried a third mutation with the addition of a mutation at codon 581 in the dhps gene. This triple: triple haplotype maybe associated with earlier treatment failure. Conclusion In northern Tanzania SP is a failed drug for treatment and its utility for prophylaxis is doubtful. The study found a new combination of parasite mutations that maybe associated with increased and earlier failure. Trial Registration ClinicalTrials.gov NCT00361114
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Clerk CA, Bruce J, Affipunguh PK, Mensah N, Hodgson A, Greenwood B, Chandramohan D. A randomized, controlled trial of intermittent preventive treatment with sulfadoxine-pyrimethamine, amodiaquine, or the combination in pregnant women in Ghana. J Infect Dis 2008; 198:1202-11. [PMID: 18752443 DOI: 10.1086/591944] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The use of sulfadoxine-pyrimethamine (SP) for intermittent preventive treatment in pregnancy (IPTp) is threatened by the spread of resistance to SP. Therefore, we studied the efficacy, safety, and tolerance of amodiaquine (AQ) or the combination of AQ and SP (SPAQ) as possible alternative treatments. METHODS The study was performed in Ghana from June 2004 through February 2007. Women were individually randomized to receive IPTp with SP (n=1328), AQ (n= 986), or SPAQ (n=1328). Incidences of anemia, peripheral anemia, and placental parasitemia at delivery were assessed for paucigravidae, as were the birth weights of their infants. Delivery outcomes and the incidence of adverse events were investigated for all women. RESULTS The prevalences of anemia (as defined by a hemoglobin concentration of <11.0 g/dL) at delivery were comparable between the SP and AQ groups and between the SP and SPAQ groups. Similarly, there was no significant difference between the SP and AQ groups or between the SP and SPAQ groups with regard to the incidences of low birth weight (LBW). Women who received AQ or SPAQ were more likely to report adverse events than were those who received SP. CONCLUSION The effects of IPTp with AQ or SPAQ on maternal anemia and LBW were comparable to the effects of IPTp with SP; however, IPTp regimens that contain AQ are unlikely to be useful as an alternative to IPTp with SP in Ghana, because of a high frequency of associated adverse events. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT00146783 .
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Abstract
Nicholas White and colleagues discuss why it is so important to conduct clinical trials of malaria treatments in pregnancy.
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Affiliation(s)
- Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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