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Schnyder JL, de Jong HK, Schlagenhauf P, Borrmann S, Hanscheid T, Grobusch MP. Discontinuing atovaquone/proguanil prophylaxis ad-hoc post-exposure and during-travel dose-sparing prophylactic regimens against P. falciparum malaria: An update with pointers for future research. Travel Med Infect Dis 2022; 49:102365. [PMID: 35661741 DOI: 10.1016/j.tmaid.2022.102365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Atovaquone/proguanil (AP) is a highly effective malaria chemoprophylaxis combination. According to current guidelines, AP is taken once daily during, and continued for seven days post exposure. A systematic review by Savelkoel et al. summarised data up to 2017 on abbreviated AP regimens, and concluded that discontinuing AP upon return may be effective, although the available data was insufficient to modify current recommendations. The same applies to other studies evaluating during-travel dose-sparing regimens. METHODS A literature search in Pubmed and Embase was performed including search terms related to AP prophylaxis and pharmacokinetics to search for recent studies on abbreviated AP regimens published since 2017. RESULTS Since the 2017 review, no new studies assessing discontinuing AP ad-hoc post-exposure prophylaxis have been published. Two new studies were identified assessing other abbreviated AP regimens; one investigated a twice-weekly AP regimen in 32 travellers, and one a three-day AP course in therapeutic dose (1000/400 mg) prior to exposure in 215 travellers. No malaria cases were detected in the study participants adhering to these regimens. CONCLUSIONS Further research would be needed if the research question is considered of sufficient importance to facilitate evidence-based decision-making to modify current guidelines, as efficacy studies in travellers are fraught with confounders. We recommend human challenge trials to study abbreviated AP regimens pertaining to malaria chemoprophylaxis as they allow for rational, subject number, time- and cost-saving trial designs.
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Affiliation(s)
- Jenny L Schnyder
- Centre for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
| | - Hanna K de Jong
- Centre for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
| | - Patricia Schlagenhauf
- University of Zurich Centre for Travel Medicine, WHO Collaborating Centre for Travellers' Health, Department of Public and Global Health, Military Medicine Biology Competence Centre, Institute for Epidemiology, Biostatistics and Prevention, Zurich, Switzerland
| | - Steffen Borrmann
- Institute of Tropical Medicine, German Centre for Infection Research (DZIF), University of Tübingen, Tübingen, Germany
| | - Thomas Hanscheid
- Instituto de Microbiologia, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Martin P Grobusch
- Centre for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands; Institute of Tropical Medicine, German Centre for Infection Research (DZIF), University of Tübingen, Tübingen, Germany; Centre de Recherches Médicales en Lambaréné (CERMEL), Lambaréné, Gabon; Masanga Medical Research Unit (MMRU), Masanga, Gabon; Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa.
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Chalon S, Chughlay MF, Abla N, Marie Tchouatieu A, Haouala A, Hutter B, Lorch U, Macintyre F. Unanticipated CNS Safety Signal in a Placebo-Controlled, Randomized Trial of Co-Administered Atovaquone-Proguanil and Amodiaquine. Clin Pharmacol Ther 2021; 111:867-877. [PMID: 34453327 PMCID: PMC9291514 DOI: 10.1002/cpt.2404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/29/2021] [Indexed: 01/28/2023]
Abstract
Atovaquone‐proguanil (ATV‐PG) plus amodiaquine (AQ) has been considered as a potential replacement for sulfadoxine‐pyrimethamine plus AQ for seasonal malaria chemoprevention in African children. This randomized, double‐blind, placebo‐controlled, parallel group study assessed the safety, tolerability, and pharmacokinetics (PKs) of ATV‐PG plus AQ in healthy adult males and females of Black sub‐Saharan African origin. Participants were randomized to four treatment groups: ATV‐PG/AQ (n = 8), ATV‐PG/placebo (n = 12), AQ/placebo (n = 12), and placebo/placebo (n = 12). Treatments were administered orally once daily for 3 days (days 1–3) at daily doses of ATV‐PQ 1000/400 mg and AQ 612 mg. Co‐administration of ATV‐PG/AQ had no clinically relevant effect on PK parameters for ATV, PG, the PG metabolite cycloguanil, AQ, or the AQ metabolite N‐desethyl‐amodiaquine. Adverse events occurred in 8 of 8 (100%) of participants receiving ATV‐PG/AQ, 11 of 12 (91.7%) receiving ATV‐PG, 11 of 12 (91.7%) receiving AQ, and 3 of 12 (25%) receiving placebo. The safety and tolerability profiles of ATV‐PG and AQ were consistent with previous reports. In the ATV‐PG/AQ group, 2 of 8 participants experienced extrapyramidal adverse effects (EPAEs) on day 3, both psychiatric and physical, which appeared unrelated to drug plasma PKs or cytochrome P450 2C8 phenotype. Although rare cases are reported with AQ administration, the high incidence of EPAE was unexpected in this small study. Owing to the unanticipated increased frequency of EPAE observed, the combination of ATV‐PQ plus AQ is not recommended for further evaluation in prophylaxis of malaria in African children.
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Affiliation(s)
| | | | - Nada Abla
- Medicines for Malaria Venture, Geneva, Switzerland
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Tessema KM, Chirove F, Sibanda P. Modeling control of foot and mouth disease with two time delays. INT J BIOMATH 2019. [DOI: 10.1142/s179352451930001x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We develop a delay ordinary differential equation model that captures the effects of prophylactic vaccination, reactive vaccination, prophylactic treatment and reactive culling on the spread of foot and mouth disease (FMD) with time delays. Simulation results from the study suggest that increasing time delay while increasing the control strategies decreases the burden of FMD. Further, the results reveal, that decreasing time delay while decreasing the control strategies increases the burden of FMD. The intermediate scenarios of either (i) increasing time delay while decreasing control or (ii) decreasing time delay while increasing control have intermediate effects on burden reduction. Thus, the implementation of effective control strategies combination can play an important role in mitigating against the FMD burden.
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Affiliation(s)
- Kassahun M. Tessema
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01 Scottsville 3209, Pietermaritzburg, South Africa
| | - Faraimunashe Chirove
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01 Scottsville 3209, Pietermaritzburg, South Africa
| | - Precious Sibanda
- School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X01 Scottsville 3209, Pietermaritzburg, South Africa
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4
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Lau CL, Ramsey L, Mills LC, Furuya-Kanamori L, Mills DJ. Drug-free Holidays: Compliance, Tolerability, and Acceptability of a 3-Day Atovaquone/Proguanil Schedule for Pretravel Malaria Chemoprophylaxis in Australian Travelers. Clin Infect Dis 2018; 69:137-143. [DOI: 10.1093/cid/ciy854] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 09/28/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Colleen L Lau
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
- Dr Deb the Travel Doctor, Travel Medicine Alliance, Brisbane, Queensland
| | - Lani Ramsey
- Travel-Bug Vaccination Clinic, Travel Medicine Alliance, Adelaide, South Australia, Australia
| | - Laura C Mills
- Dr Deb the Travel Doctor, Travel Medicine Alliance, Brisbane, Queensland
| | - Luis Furuya-Kanamori
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
- Department of Population Medicine, College of Medicine, Qatar University, Doha
| | - Deborah J Mills
- Dr Deb the Travel Doctor, Travel Medicine Alliance, Brisbane, Queensland
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5
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Savelkoel J, Binnendijk KH, Spijker R, van Vugt M, Tan K, Hänscheid T, Schlagenhauf P, Grobusch MP. Abbreviated atovaquone-proguanil prophylaxis regimens in travellers after leaving malaria-endemic areas: A systematic review. Travel Med Infect Dis 2018; 21:3-20. [PMID: 29242073 PMCID: PMC10956543 DOI: 10.1016/j.tmaid.2017.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 12/09/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND We evaluated existing data on the prophylactic efficacy of atovaquone-proguanil (AP) in order to determine whether prophylaxis in travellers can be discontinued on the day of return from a malaria-endemic area instead of seven days after return as per currently recommended post-travel schedule. METHODS PubMed and Embase databases were searched to identify relevant studies. This PROSPERO-registered systematic review followed PRISMA guidelines. The search strategy included terms or synonyms relevant to AP combined with terms to identify articles relating to prophylactic use of AP and inhibitory and half-life properties of AP. Studies considered for inclusion were: randomized controlled trials, cohort studies, quasi-experimental studies, open-label trials, patient-control studies, cross-sectional studies; as well as case-series and non-clinical studies. Data on study design, characteristics of participants, interventions, and outcomes were extracted. Primary outcomes considered relevant were prophylactic efficacy and prolonged inhibitory activity and half-life properties of AP. RESULTS The initial search identified 1,482 publications, of which 40 were selected based on screening. Following full text review, 32 studies were included and categorized into two groups, namely studies in support of the current post-travel regimen (with a total of 2,866 subjects) and studies in support of an alternative regimen (with a total of 533 subjects). CONCLUSION There is limited direct and indirect evidence to suggest that an abbreviated post-travel regimen for AP may be effective. Proguanil, however, has a short half-life and is essential for the synergistic effect of the combination. Stopping AP early may result in mono-prophylaxis with atovaquone and possibly select for atovaquone-resistant parasites. Furthermore, the quality of the studies in support of the current post-travel regimen outweighs the quality of the studies in support of an alternative short, post-travel regimen, and the total sample size of the studies to support stopping AP early comprises a small percentage of the total sample size of the studies performed to establish the efficacy of the current AP regimen. Additional research is required - especially from studies evaluating impact on malaria parasitaemia and clinical illness and conducted among travellers in high malaria risk settings - before an abbreviated regimen can be recommended in current practice. PROSPERO REGISTRATION NUMBER CRD42017055244.
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Affiliation(s)
- Jelmer Savelkoel
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, DD1100 Amsterdam, The Netherlands
| | - Klaas Hendrik Binnendijk
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, DD1100 Amsterdam, The Netherlands
| | - Rene Spijker
- Medical Library, Academic Medical Center, University of Amsterdam, Meibergdreef 9, DD1100 Amsterdam, The Netherlands
| | - Michèle van Vugt
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, DD1100 Amsterdam, The Netherlands
| | - Kathrine Tan
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Thomas Hänscheid
- Instituto de Medicina Molecular and Department of Microbiology, University of Lisbon, Lisbon, Portugal
| | - Patricia Schlagenhauf
- University of Zürich Travel Clinic, WHO Collaborating Centre for Travellers' Health, Institute for Epidemiology, Biostatistics and Prevention, University of Zurich, Zurich, Switzerland
| | - Martin Peter Grobusch
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Academic Medical Center, University of Amsterdam, Meibergdreef 9, DD1100 Amsterdam, The Netherlands.
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Abstract
Alternative approaches to malaria chemoprophylaxis are discussed in light of the difficulties of executing clinical trials within limits of infection rates and ethics.
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Affiliation(s)
- Dennis Shanks
- Australian Army Malaria Institute, Enoggera, QLD 4051, Australia School of Public Health, University of Queensland, Brisbane, Australia
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7
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Abstract
Malaria chemotherapy is under constant threat from the emergence and spread of multidrug resistance of Plasmodium falciparum. Resistance has been observed to almost all currently used antimalarials. Some drugs are also limited by toxicity. A fundamental component of the strategy for malaria chemotherapy is based on prompt, effective and safe antimalarial drugs. To counter the threat of resistance of P. falciparum to existing monotherapeutic regimens, current malaria treatment is based principally on the artemisinin group of compounds, either as monotherapy or artemisinin-based combination therapies for treatment of both uncomplicated and severe falciparum malaria. Key advantages of artemisinins over the conventional antimalarials include their rapid and potent action, with good tolerability profiles. Their action also covers transmissible gametocytes, resulting in decreased disease transmission. Up to now there has been no prominent report of drug resistance to this group of compounds. Treatment of malaria in pregnant women requires special attention in light of limited treatment options caused by potential teratogenicity coupled with a paucity of safety data for the mother and fetus. Treatment of other malaria species is less problematic and chloroquine is still the drug of choice, although resistance of P. vivax to chloroquine has been reported. Multiple approaches to the identification of new antimalarial targets and promising antimalarial drugs are being pursued in order to cope with drug resistance.
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Affiliation(s)
- Kesara Na-Bangchang
- Faculty of Allied Health Sciences, Thammasat University (Rangsit Campus), Paholyothin Road, Klong Luang District, Pathumtanee 12121, Thailand.
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Deye GA, Miller RS, Miller L, Salas CJ, Tosh D, Macareo L, Smith BL, Fracisco S, Clemens EG, Murphy J, Sousa JC, Dumler JS, Magill AJ. Prolonged Protection Provided by a Single Dose of Atovaquone-Proguanil for the Chemoprophylaxis of Plasmodium falciparum Malaria in a Human Challenge Model. Clin Infect Dis 2011; 54:232-9. [DOI: 10.1093/cid/cir770] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Cyclodextrin/poly(anhydride) nanoparticles as drug carriers for the oral delivery of atovaquone. Biomed Microdevices 2011; 13:1015-25. [DOI: 10.1007/s10544-011-9571-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Neff CP, Ndolo T, Tandon A, Habu Y, Akkina R. Oral pre-exposure prophylaxis by anti-retrovirals raltegravir and maraviroc protects against HIV-1 vaginal transmission in a humanized mouse model. PLoS One 2010; 5:e15257. [PMID: 21203568 PMCID: PMC3006206 DOI: 10.1371/journal.pone.0015257] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 11/02/2010] [Indexed: 12/31/2022] Open
Abstract
Sexual HIV-1 transmission by vaginal route is the most predominant mode of viral transmission, resulting in millions of new infections every year. In the absence of an effective vaccine, there is an urgent need to develop other alternative methods of pre-exposure prophylaxis (PrEP). Many novel drugs that are currently approved for clinical use also show great potential to prevent viral sexual transmission when administered systemically. A small animal model that permits rapid preclinical evaluation of potential candidates for their systemic PrEP efficacy will greatly enhance progress in this area of investigation. We have previously shown that RAG-hu humanized mouse model permits HIV-1 mucosal transmission via both vaginal and rectal routes and displays CD4 T cell loss typical to that seen in the human. Thus far systemic PrEP studies have been primarily limited to RT inhibitors exemplified by tenofovir and emtricitabine. In these proof-of-concept studies we evaluated two new classes of clinically approved drugs with different modes of action namely, an integrase inhibitor raltegravir and a CCR5 inhibitor maraviroc as potential systemically administered chemo-prophylactics. Our results showed that oral administration of either of these drugs fully protects against vaginal HIV-1 challenge in the RAG-hu mouse model. Based on these results both these drugs show great promise for further development as orally administered PrEPs.
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Affiliation(s)
- C. Preston Neff
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Thomas Ndolo
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Apurva Tandon
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Yuichiro Habu
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ramesh Akkina
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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Current World Literature. Curr Opin Neurol 2009; 22:321-9. [DOI: 10.1097/wco.0b013e32832cf9cb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Craft JC. Challenges facing drug development for malaria. Curr Opin Microbiol 2008; 11:428-33. [PMID: 18824124 DOI: 10.1016/j.mib.2008.09.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Accepted: 09/02/2008] [Indexed: 11/16/2022]
Abstract
Malaria is a significant cause of morbidity and mortality in the developing world. Until recently malaria was winning but with increase in funding particularly from philanthropic groups the ability to control malaria is again possible. There are still many challenges to developing the next generations of anti-malarials. This article will briefly discuss the challenges and the advance that are being made.
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