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1.
PLoS One ; 19(5): e0303289, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38722891

RESUMO

Malaria and Human Immunodeficiency Virus infections are among the top 10 causes of death in low income countries. Furthermore, many medicines used in these treatment areas are substandard, which contributes to the high death rate. Using a monitoring system to identify substandard and falsified medicines, the study aims to evaluate the quality of antimalarial and antiretroviral medicines in Sahel countries, assessing site conditions, compliance of medicines with pharmacopoeia tests, formulation equivalence with a reference medicine, and the influence of climate on quality attributes. Ultra Performance Liquid Chromatography methods for eight active pharmaceutical ingredients were validated following the International Conference for Harmonization guideline for its detection and quantification. Quality control consists of visual inspections to detect any misinformation or imperfections and pharmacopeial testing to determine the quality of pharmaceutical products. Medicines which complied with uniformity dosage units and dissolution tests were stored under accelerated conditions for 6 months. Artemether/Lumefantrine and Lopinavir/Ritonavir formulations failed uniformity dosage units and disintegration tests respectively, detecting a total of 28.6% substandard medicines. After 6 months stored under accelerated conditions (40 °C // 75% relative humidity) simulating climatic conditions in Sahel countries, some medicines failed pharmacopeia tests. It demonstrated the influence of these two factors in their quality attributes. This study emphasizes the need of certified quality control laboratories as well as the need for regulatory systems to maintain standards in pharmaceutical manufacturing and distribution in these countries, especially when medicines are transported to rural areas where these climatic conditions are harsher.


Assuntos
Antimaláricos , Controle de Qualidade , Antimaláricos/análise , Antimaláricos/normas , Humanos , Antirretrovirais/análise , Saúde Pública , Ritonavir/análise , Ritonavir/uso terapêutico , Administração Oral , Medicamentos Fora do Padrão/análise , Infecções por HIV/tratamento farmacológico , Malária/tratamento farmacológico , Lopinavir/análise , Lopinavir/uso terapêutico
2.
Nat Commun ; 15(1): 3817, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714692

RESUMO

Standard diagnostics used in longitudinal antimalarial studies are unable to characterize the complexity of submicroscopic parasite dynamics, particularly in high transmission settings. We use molecular markers and amplicon sequencing to characterize post-treatment stage-specific malaria parasite dynamics during a 42 day randomized trial of 3- versus 5 day artemether-lumefantrine in 303 children with and without HIV (ClinicalTrials.gov number NCT03453840). The prevalence of parasite-derived 18S rRNA is >70% in children throughout follow-up, and the ring-stage marker SBP1 is detectable in over 15% of children on day 14 despite effective treatment. We find that the extended regimen significantly lowers the risk of recurrent ring-stage parasitemia compared to the standard 3 day regimen, and that higher day 7 lumefantrine concentrations decrease the probability of ring-stage parasites in the early post-treatment period. Longitudinal amplicon sequencing reveals remarkably dynamic patterns of multiclonal infections that include new and persistent clones in both the early post-treatment and later time periods. Our data indicate that post-treatment parasite dynamics are highly complex despite efficacious therapy, findings that will inform strategies to optimize regimens in the face of emerging partial artemisinin resistance in Africa.


Assuntos
Antimaláricos , Combinação Arteméter e Lumefantrina , Plasmodium falciparum , Humanos , Combinação Arteméter e Lumefantrina/uso terapêutico , Antimaláricos/uso terapêutico , Antimaláricos/administração & dosagem , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Pré-Escolar , Criança , Masculino , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Feminino , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , RNA Ribossômico 18S/genética , Malária/tratamento farmacológico , Malária/parasitologia , Lactente , Infecções por HIV/tratamento farmacológico , Artemisininas/uso terapêutico , Artemisininas/administração & dosagem
3.
PLoS One ; 19(5): e0299517, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38713730

RESUMO

Artemisinin-based combination therapies (ACTs) represent one of the mainstays of malaria control. Despite evidence of the risk of ACTs resistant infections in resource-limited countries, studies on the rational use of ACTs to inform interventions and prevent their emergence and/or spread are limited. The aim of this study was designed to analyze practices toward ACTs use for treating the treatment of uncomplicated malaria (UM) in an urban community. Between November 2015 and April 2016, a cross-sectional and prospective study was conducted in the 6 health facilities and all pharmacies in the Douala 5e subdivision, Cameroon. Anonymous interviews including both open- and closed-ended questions were conducted with selected participants among drug prescribers, patients attending the health facilities, and customers visiting the pharmacies. Data analysis was performed using StataSE11 software (version 11 SE). A total of 41 prescribers were included in the study. All were aware of national treatment guidelines, but 37.7% reported not waiting for test results before prescribing an antimalarial drug, and the main reason being stock-outs at health facilities. Likewise, artemether+lumefantrine/AL (81%) and dihydroartemisinin+piperaquine (63.5%) were the most commonly used first- and second-line drugs respectively. Biological tests were requested in 99.2% (128/129) of patients in health facilities, 60.0% (74) were performed and 6.2% were rationally managed. Overall 266 (35%) of 760 customers purchased antimalarial drugs, of these, 261 (98.1%) agreed to participate and of these, 69.4% purchased antimalarial drugs without a prescription. ACTs accounted for 90.0% of antimalarials purchased from pharmacies, of which AL was the most commonly prescribed antimalarial drug (67.1%), and only 19.5% of patients were appropriately dispensed. The current data suggest a gap between the knowledge and practices of prescribers as well as patients and customers misconceptions regarding the use of ACTs in Douala 5e subdivision. Despite government efforts to increase public awareness regarding the use of ACTs as first-line treatment for UM, our findings point out a critical need for the development, implementation and scaling-up of control strategies and continuing health education for better use of ACTs (prescription and dispensing) in Cameroon.


Assuntos
Antimaláricos , Artemisininas , Instalações de Saúde , Malária , Farmácias , Humanos , Artemisininas/uso terapêutico , Camarões , Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Estudos Transversais , Feminino , Masculino , Adulto , Estudos Prospectivos , Quimioterapia Combinada , Pessoa de Meia-Idade , Adulto Jovem , Adolescente
4.
Parasitol Res ; 123(5): 209, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38740597

RESUMO

Artemisinin (ART) combination therapy is the main treatment for malaria. Pfk13 mutations (or K13 mutations, Kelch 13) are associated with ART resistance. This study aims to conduct a systematic review and meta-analysis of the prevalence of K13 mutations with ART resistance in malaria-endemic countries. An electronic search of studies in 2018 and a manual search in 2020 were performed to identify relevant studies. The risk of bias was assessed using the National Institutes of Health (NIH) quality assessment tool for observational cohort and cross-sectional studies. Data analysis was performed using R 4.1.0. Heterogeneity was estimated using the statistic I2 and Cochran Q test. A total of 170 studies were included in our review. Of these, 55 studies investigated the prevalence of K13 mutations in Southeast Asia. The meta-analysis showed that Southeast Asia had the highest prevalence of K13 mutations, whereas Africa, South America, Oceania, and other Asian countries outside Southeast Asia had a low prevalence of K13 mutations. The C580Y mutation was the most common in Southeast Asia with 35.5% (95%CI: 25.4-46.4%), whereas the dominant mutation in Africa was K189T (22.8%, 95%CI: 7.6-43.2%). This study revealed the emergence of ART resistance associated with K13 mutations in Southeast Asia. The diversity of each type of K13 mutation in other regions was also reported.


Assuntos
Antimaláricos , Artemisininas , Polimorfismo Genético , Artemisininas/uso terapêutico , Humanos , Antimaláricos/uso terapêutico , Prevalência , Resistência a Medicamentos/genética , Plasmodium falciparum/genética , Plasmodium falciparum/efeitos dos fármacos , Malária/tratamento farmacológico , Malária/epidemiologia , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Mutação , Proteínas de Protozoários/genética , Sudeste Asiático/epidemiologia
5.
Int J Mol Sci ; 25(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38673995

RESUMO

In recent decades, neglected tropical diseases and poverty-related diseases have become a serious health problem worldwide. Among these pathologies, human African trypanosomiasis, and malaria present therapeutic problems due to the onset of resistance, toxicity problems and the limited spectrum of action. In this drug discovery process, rhodesain and falcipain-2, of Trypanosoma brucei rhodesiense and Plasmodium falciparum, are currently considered the most promising targets for the development of novel antitrypanosomal and antiplasmodial agents, respectively. Therefore, in our study we identified a novel lead-like compound, i.e., inhibitor 2b, which we proved to be active against both targets, with a Ki = 5.06 µM towards rhodesain and an IC50 = 40.43 µM against falcipain-2.


Assuntos
Inibidores de Cisteína Proteinase , Nitrilas , Plasmodium falciparum , Trypanosoma brucei rhodesiense , Tripanossomíase Africana , Humanos , Antimaláricos/uso terapêutico , Antimaláricos/farmacologia , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Inibidores de Cisteína Proteinase/uso terapêutico , Inibidores de Cisteína Proteinase/química , Malária/tratamento farmacológico , Nitrilas/uso terapêutico , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/metabolismo , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Trypanosoma brucei rhodesiense/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico
6.
BMC Health Serv Res ; 24(1): 484, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637742

RESUMO

BACKGROUND: Malaria in pregnancy remains a major global public health problem. Intermittent prophylaxis treatment of malaria in pregnancy with Sulphadoxine-pyrimethamine and co-trimoxazole is efficacious for prevention of malaria in pregnancy HIV negative and positive women, respectively. However, uptake of the recommended doses of therapies has remained suboptimal in Uganda, majorly due to inadequate knowledge among pregnant women. Therefore, this study aimed to explore attitudes and perceptions towards developing an educational video for malaria preventive therapy. METHODS: We conducted an exploratory study with qualitative methods among pregnant women attending antenatal care at Kisenyi Health Center IV (KHCIV), health workers from KHCIV, and officials from the Ministry of Health. The study was conducted at KHCIV from October 2022 to March 2023. Focus group discussions (FGD) were conducted among purposively selected pregnant women and key informant interviews (KII) among health workers and Ministry of Health officials. Data were analyzed using inductive and deductive thematic methods in atlas ti.8. RESULTS: A total of five FGDs comprising of 7-10 pregnant women were conducted; and KIIs were conducted among four mid-wives, two obstetricians, and two Ministry of Health officials. Generally, all respondents mentioned a need for interventions to improve malaria preventive knowledge among pregnant women; were positive about developing an educative video for malaria preventive therapy in pregnancy; and suggested a short, concise, and edutaining video focusing both the benefits of taking and risks of not taking malaria preventive therapy. They proposed that women may be encouraged to view the video as soon as they conceive and throughout the pregnancy. It also was suggested that the video may be viewed on television sets in maternal and reproductive health clinics and homes, and on smart phones. CONCLUSION: Pregnant women, health workers, and Ministry of Health officials were positive about the development of a short edutaining video on malaria preventive therapy that focuses on both benefits of taking and risks of not taking the malaria preventive therapy in pregnancy. This information guided the video development and therefore, in the development of health educative videos, client and stakeholder inputs may always be solicited.


Assuntos
Antimaláricos , Malária , Feminino , Gravidez , Humanos , Gestantes , Uganda , Conhecimentos, Atitudes e Prática em Saúde , Malária/prevenção & controle , Malária/tratamento farmacológico , Sulfadoxina/uso terapêutico , Pirimetamina/uso terapêutico , Cuidado Pré-Natal/métodos , Combinação de Medicamentos , Antimaláricos/uso terapêutico
7.
Sci Adv ; 10(16): eadk4492, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38640243

RESUMO

Approximately 3.3 billion people live with the threat of Plasmodium vivax malaria. Infection can result in liver-localized hypnozoites, which when reactivated cause relapsing malaria. This work demonstrates that an enzyme-cleavable polymeric prodrug of tafenoquine addresses key requirements for a mass administration, eradication campaign: excellent subcutaneous bioavailability, complete parasite control after a single dose, improved therapeutic window compared to the parent oral drug, and low cost of goods sold (COGS) at less than $1.50 per dose. Liver targeting and subcutaneous dosing resulted in improved liver:plasma exposure profiles, with increased efficacy and reduced glucose 6-phosphate dehydrogenase-dependent hemotoxicity in validated preclinical models. A COGS and manufacturability analysis demonstrated global scalability, affordability, and the ability to redesign this fully synthetic polymeric prodrug specifically to increase global equity and access. Together, this polymer prodrug platform is a candidate for evaluation in human patients and shows potential for P. vivax eradication campaigns.


Assuntos
Antimaláricos , Malária Vivax , Malária , Humanos , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Aminoquinolinas/efeitos adversos , Malária/tratamento farmacológico , Malária Vivax/tratamento farmacológico , Malária Vivax/induzido quimicamente , Fígado
8.
Malar J ; 23(1): 95, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582830

RESUMO

BACKGROUND: The use of artemisinin-based combination therapy (ACT) is recommended by the World Health Organization for the treatment of uncomplicated falciparum malaria. Artemether-lumefantrine (AL) is the most widely adopted first-line ACT for uncomplicated malaria in sub-Saharan Africa (SSA), including mainland Tanzania, where it was introduced in December 2006. The WHO recommends regular assessment to monitor the efficacy of the first-line treatment specifically considering that artemisinin partial resistance was reported in Greater Mekong sub-region and has been confirmed in East Africa (Rwanda and Uganda). The main aim of this study was to assess the efficacy and safety of AL for the treatment of uncomplicated falciparum malaria in mainland Tanzania. METHODS: A single-arm prospective anti-malarial drug efficacy trial was conducted in Kibaha, Mlimba, Mkuzi, and Ujiji (in Pwani, Morogoro, Tanga, and Kigoma regions, respectively) in 2018. The sample size of 88 patients per site was determined based on WHO 2009 standard protocol. Participants were febrile patients (documented axillary temperature ≥ 37.5 °C and/or history of fever during the past 24 h) aged 6 months to 10 years. Patients received a 6-dose AL regimen by weight twice a day for 3 days. Clinical and parasitological parameters were monitored during 28 days of follow-up to evaluate the drug efficacy and safety. RESULTS: A total of 653 children were screened for uncomplicated malaria and 349 (53.7%) were enrolled between April and August 2018. Of the enrolled children, 345 (98.9%) completed the 28 days of follow-up or attained the treatment outcomes. There were no early treatment failures, but recurrent infections were higher in Mkuzi (35.2%) and Ujiji (23%). By Kaplan-Meier analysis of polymerase chain reaction (PCR) uncorrected adequate clinical and parasitological response (ACPR) ranged from 63.4% in Mkuzi to 85.9% in Mlimba, while PCR-corrected ACPR on day 28 varied from 97.6% in Ujiji to 100% in Mlimba. The drug was well tolerated; the commonly reported adverse events were cough, runny nose, and abdominal pain. No serious adverse event was reported. CONCLUSION: This study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria. The high number of recurrent infections were mainly due to new infections, indicating the necessity of utilizing alternative artemisinin-based combinations, such as artesunate amodiaquine, which provide a significantly longer post-treatment prophylactic effect.


Assuntos
Antimaláricos , Artemisininas , Malária Falciparum , Malária , Criança , Humanos , Antimaláricos/efeitos adversos , Combinação Arteméter e Lumefantrina/efeitos adversos , Tanzânia , Reinfecção/induzido quimicamente , Reinfecção/tratamento farmacológico , Artemisininas/efeitos adversos , Artemeter/uso terapêutico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/prevenção & controle , Amodiaquina/uso terapêutico , Malária/tratamento farmacológico , Febre/tratamento farmacológico , Combinação de Medicamentos , Etanolaminas/efeitos adversos , Plasmodium falciparum
9.
PLoS Comput Biol ; 20(4): e1012017, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38626207

RESUMO

Current malaria elimination targets must withstand a colossal challenge-resistance to the current gold standard antimalarial drug, namely artemisinin derivatives. If artemisinin resistance significantly expands to Africa or India, cases and malaria-related deaths are set to increase substantially. Spatial information on the changing levels of artemisinin resistance in Southeast Asia is therefore critical for health organisations to prioritise malaria control measures, but available data on artemisinin resistance are sparse. We use a comprehensive database from the WorldWide Antimalarial Resistance Network on the prevalence of non-synonymous mutations in the Kelch 13 (K13) gene, which are known to be associated with artemisinin resistance, and a Bayesian geostatistical model to produce spatio-temporal predictions of artemisinin resistance. Our maps of estimated prevalence show an expansion of the K13 mutation across the Greater Mekong Subregion from 2000 to 2022. Moreover, the period between 2010 and 2015 demonstrated the most spatial change across the region. Our model and maps provide important insights into the spatial and temporal trends of artemisinin resistance in a way that is not possible using data alone, thereby enabling improved spatial decision support systems on an unprecedented fine-scale spatial resolution. By predicting for the first time spatio-temporal patterns and extents of artemisinin resistance at the subcontinent level, this study provides critical information for supporting malaria elimination goals in Southeast Asia.


Assuntos
Antimaláricos , Artemisininas , Teorema de Bayes , Resistência a Medicamentos , Artemisininas/farmacologia , Sudeste Asiático/epidemiologia , Resistência a Medicamentos/genética , Antimaláricos/farmacologia , Humanos , Análise Espaço-Temporal , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Mutação , Malária/tratamento farmacológico , Malária/epidemiologia , Biologia Computacional , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Malária Falciparum/epidemiologia
10.
Malar J ; 23(1): 120, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664678

RESUMO

BACKGROUND: The increased availability and use of malaria rapid diagnostic test (RDT) by primary healthcare (PHC) workers has made universal diagnostic testing before malaria treatment more feasible. However, to meaningfully resolve the problem of over-treatment with artemisinin-based combination therapy and the heightened risk of selection pressure and drug resistance, there should be appropriate response (non-prescription of anti-malarial drugs) following a negative RDT result by PHC workers. This study explored the determinants of the use of RDT and anti-malarial drug prescription practices by PHC workers in Ebonyi state, Nigeria. METHODS: Between March 2 and 10, 2020, three focus group discussions were conducted in English with 23 purposively-selected consenting PHC workers involved in the diagnosis and treatment of malaria. Data was analysed thematically as informed by the method by Braun and Clarke. RESULTS: The determinants of the use of RDT for malaria diagnosis were systemic (RDT availability and patient load), provider related (confidence in RDT and the desire to make correct diagnosis, PHC worker's knowledge and training, and fear to prick a patient), client related (fear of needle prick and refusal to receive RDT, and self-diagnosis of malaria, based on symptoms, and insistence on not receiving RDT), and RDT-related (the ease of conducting and interpreting RDT). The determinants of anti-malarial drug prescription practices were systemic (drug availability and cost) and drug related (effectiveness and side-effects of the drugs). The determinants of the prescription of anti-malarial drugs following negative RDT were provider related (the desire to make more money and limited confidence in RDT) and clients' demand while unnecessary co-prescription of antibiotics with anti-malarial drugs following positive RDT was determined by the desire to make more money. CONCLUSIONS: This evidence highlights many systemic, provider, client, and RDT/drug related determinants of PHC workers' use of RDT and anti-malarial drug prescription practices that should provide tailored guidance for relevant health policy actions in Ebonyi state, Nigeria, and similar settings.


Assuntos
Antimaláricos , Testes Diagnósticos de Rotina , Pessoal de Saúde , Malária , Atenção Primária à Saúde , Nigéria , Antimaláricos/uso terapêutico , Testes Diagnósticos de Rotina/estatística & dados numéricos , Malária/tratamento farmacológico , Malária/diagnóstico , Humanos , Pessoal de Saúde/estatística & dados numéricos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Prescrições de Medicamentos/estatística & dados numéricos , Grupos Focais , Pesquisa Qualitativa , Testes de Diagnóstico Rápido
11.
Malar J ; 23(1): 101, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594679

RESUMO

BACKGROUND: Artemisinin-based combination therapy (ACT) has been a major contributor to the substantial reductions in global malaria morbidity and mortality over the last decade. In Tanzania, artemether-lumefantrine (AL) was introduced as the first-line treatment for uncomplicated Plasmodium falciparum malaria in 2006. The World Health Organization (WHO) recommends regular assessment and monitoring of the efficacy of the first-line treatment, specifically considering that artemisinin resistance has been confirmed in the Greater Mekong sub-region. This study's main aim was to assess the efficacy and safety of AL for treating uncomplicated P. falciparum malaria in Tanzania. METHODS: This was a single-arm prospective antimalarial drug efficacy trial conducted in four of the eight National Malaria Control Programme (NMCP) sentinel sites in 2019. The trial was carried out in outpatient health facilities in Karume-Mwanza region, Ipinda-Mbeya region, Simbo-Tabora region, and Nagaga-Mtwara region. Children aged six months to 10 years with microscopy confirmed uncomplicated P. falciparum malaria who met the inclusion criteria were recruited based on the WHO protocol. The children received AL (a 6-dose regimen of AL twice daily for three days). Clinical and parasitological parameters were monitored during follow-up over 28 days to evaluate drug efficacy. RESULTS: A total of 628 children were screened for uncomplicated malaria, and 349 (55.6%) were enrolled between May and September 2019. Of the enrolled children, 343 (98.3%) completed the 28-day follow-up or attained the treatment outcomes. There were no early treatment failures; recurrent infections during follow-up were common at two sites (Karume 29.5%; Simbo 18.2%). PCR-corrected adequate clinical and parasitological response (ACPR) by survival analysis to AL on day 28 of follow-up varied from 97.7% at Karume to 100% at Ipinda and Nagaga sites. The commonly reported adverse events were cough, skin pallor, and abdominal pain. The drug was well tolerated, and no serious adverse event was reported. CONCLUSION: This study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria in Tanzania in 2019. The high recurrent infections were mainly due to new infections, highlighting the potential role of introducing alternative artemisinin-based combinations that offer improved post-treatment prophylaxis, such as artesunate-amodiaquine (ASAQ).


Assuntos
Antimaláricos , Artemisininas , Malária Falciparum , Malária , Criança , Humanos , Lactente , Antimaláricos/efeitos adversos , Combinação Arteméter e Lumefantrina/efeitos adversos , Tanzânia , Reinfecção/induzido quimicamente , Reinfecção/tratamento farmacológico , Estudos Prospectivos , Combinação de Medicamentos , Artemeter/uso terapêutico , Malária Falciparum/tratamento farmacológico , Artemisininas/efeitos adversos , Amodiaquina/uso terapêutico , Malária/tratamento farmacológico , Resultado do Tratamento , Plasmodium falciparum
12.
Clin Transl Sci ; 17(4): e13738, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38594824

RESUMO

Drug resistance to sulfadoxine-pyrimethamine and amodiaquine threatens the efficacy of malaria chemoprevention interventions in children and pregnant women. Combining pyronaridine (PYR) and piperaquine (PQP), both components of approved antimalarial therapies, has the potential to protect vulnerable populations from severe malaria. This randomized, double-blind, placebo-controlled (double-dummy), parallel-group, single site phase I study in healthy adult males or females of Black sub-Saharan African ancestry investigated the safety, tolerability, and pharmacokinetics of PYR + PQP (n = 15), PYR + placebo (n = 8), PQP + placebo (n = 8), and double placebo (n = 6) administered orally once daily for 3 days at the registered dose for the treatment of uncomplicated malaria. All participants completed the study. Forty-five adverse events were reported in 26 participants, most (41/45) were mild/moderate in severity, with no serious adverse events, deaths, or study withdrawals. Adverse events were reported in 66.7% (10/15) of participants administered PYR + PQP, 87.5% (7/8) with PYR + placebo, 50.0% (4/8) with PQP + placebo, and 83.3% (5/6) with placebo. For PYR containing regimens, five of 23 participants had asymptomatic transient increases in alanine and/or aspartate aminotransferase. With PQP containing regimens, four of 23 participants had mild Fridericia-corrected QT interval prolongation. Liver enzyme elevations and prolonged QTc interval were consistent with observations for PYR-artesunate and dihydroartemisinin-PQP, respectively, administered to healthy adults and malaria patients. Increases in PYR and PQP exposures were observed following co-administration versus placebo, with substantial interparticipant variability. The findings suggest that PYR + PQP may have potential in chemoprevention strategies. Further studies are needed in the target populations to assess chemoprotective efficacy and define the benefit-risk profile, with special considerations regarding hepatic and cardiac safety.


Assuntos
Malária Falciparum , Malária , Naftiridinas , Piperazinas , Quinolinas , Adulto , Criança , Masculino , Humanos , Feminino , Gravidez , Malária Falciparum/tratamento farmacológico , Malária/tratamento farmacológico , Malária/prevenção & controle , Método Duplo-Cego , África Subsaariana
13.
Cell Chem Biol ; 31(4): 743-759.e8, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38593807

RESUMO

Identification of new druggable protein targets remains the key challenge in the current antimalarial development efforts. Here we used mass-spectrometry-based cellular thermal shift assay (MS-CETSA) to identify potential targets of several antimalarials and drug candidates. We found that falcilysin (FLN) is a common binding partner for several drug candidates such as MK-4815, MMV000848, and MMV665806 but also interacts with quinoline drugs such as chloroquine and mefloquine. Enzymatic assays showed that these compounds can inhibit FLN proteolytic activity. Their interaction with FLN was explored systematically by isothermal titration calorimetry and X-ray crystallography, revealing a shared hydrophobic pocket in the catalytic chamber of the enzyme. Characterization of transgenic cell lines with lowered FLN expression demonstrated statistically significant increases in susceptibility toward MK-4815, MMV000848, and several quinolines. Importantly, the hydrophobic pocket of FLN appears amenable to inhibition and the structures reported here can guide the development of novel drugs against malaria.


Assuntos
Antimaláricos , Malária , Metilaminas , Quinolinas , Humanos , Antimaláricos/química , Malária/tratamento farmacológico , Fenóis/uso terapêutico , Quinolinas/farmacologia , Quinolinas/metabolismo , Desenvolvimento de Medicamentos
14.
ACS Infect Dis ; 10(4): 1286-1297, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38556981

RESUMO

Malaria is caused by parasites of the Plasmodium genus and remains one of the most pressing human health problems. The spread of parasites resistant to or partially resistant to single or multiple drugs, including frontline antimalarial artemisinin and its derivatives, poses a serious threat to current and future malaria control efforts. In vitro drug assays are important for identifying new antimalarial compounds and monitoring drug resistance. Due to its robustness and ease of use, the [3H]-hypoxanthine incorporation assay is still considered a gold standard and is widely applied, despite limited sensitivity and the dependence on radioactive material. Here, we present a first-of-its-kind chemiluminescence-based antimalarial drug screening assay. The effect of compounds on P. falciparum is monitored by using a dioxetane-based substrate (AquaSpark ß-D-galactoside) that emits high-intensity luminescence upon removal of a protective group (ß-D-galactoside) by a transgenic ß-galactosidase reporter enzyme. This biosensor enables highly sensitive, robust, and cost-effective detection of asexual, intraerythrocytic P. falciparum parasites without the need for parasite enrichment, washing, or purification steps. We are convinced that the ultralow detection limit of less than 100 parasites of the presented biosensor system will become instrumental in malaria research, including but not limited to drug screening.


Assuntos
Antimaláricos , Antagonistas do Ácido Fólico , Malária Falciparum , Malária , Humanos , Antimaláricos/farmacologia , Plasmodium falciparum , Malária/tratamento farmacológico , Malária Falciparum/parasitologia , Antagonistas do Ácido Fólico/farmacologia , Galactosídeos/farmacologia , Galactosídeos/uso terapêutico
15.
Malar J ; 23(1): 92, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570791

RESUMO

BACKGROUND: Artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) are the currently recommended first- and second-line therapies for uncomplicated Plasmodium falciparum infections in Togo. This study assessed the efficacy of these combinations, the proportion of Day3-positive patients (D3 +), the proportion of molecular markers associated with P. falciparum resistance to anti-malarial drugs, and the variable performance of HRP2-based malaria rapid diagnostic tests (RDTs). METHODS: A single arm prospective study evaluating the efficacy of AL and DP was conducted at two sites (Kouvé and Anié) from September 2021 to January 2022. Eligible children were enrolled, randomly assigned to treatment at each site and followed up for 42 days after treatment initiation. The primary endpoint was polymerase chain reaction (PCR) adjusted adequate clinical and parasitological response (ACPR). At day 0, samples were analysed for mutations in the Pfkelch13, Pfcrt, Pfmdr-1, dhfr, dhps, and deletions in the hrp2/hrp3 genes. RESULTS: A total of 179 and 178 children were included in the AL and DP groups, respectively. After PCR correction, cure rates of patients treated with AL were 97.5% (91.4-99.7) at day 28 in Kouvé and 98.6% (92.4-100) in Anié, whereas 96.4% (CI 95%: 89.1-98.8) and 97.3% (CI 95%: 89.5-99.3) were observed at day 42 in Kouvé and Anié, respectively. The cure rates of patients treated with DP at day 42 were 98.9% (CI 95%: 92.1-99.8) in Kouvé and 100% in Anié. The proportion of patients with parasites on day 3 (D3 +) was 8.5% in AL and 2.6% in DP groups in Anié and 4.3% in AL and 2.1% DP groups in Kouvé. Of the 357 day 0 samples, 99.2% carried the Pfkelch13 wild-type allele. Two isolates carried nonsynonymous mutations not known to be associated with artemisinin partial resistance (ART-R) (A578S and A557S). Most samples carried the Pfcrt wild-type allele (97.2%). The most common Pfmdr-1 allele was the single mutant 184F (75.6%). Among dhfr/dhps mutations, the quintuple mutant haplotype N51I/C59R/S108N + 437G/540E, which is responsible for SP treatment failure in adults and children, was not detected. Single deletions in hrp2 and hrp3 genes were detected in 1/357 (0.3%) and 1/357 (0.3%), respectively. Dual hrp2/hrp3 deletions, which could affect the performances of HRP2-based RDTs, were not observed. CONCLUSION: The results of this study confirm that the AL and DP treatments are highly effective. The absence of the validated Pfkelch13 mutants in the study areas suggests the absence of ART -R, although a significant proportion of D3 + cases were found. The absence of dhfr/dhps quintuple or sextuple mutants (quintuple + 581G) supports the continued use of SP for IPTp during pregnancy and in combination with amodiaquine for seasonal malaria chemoprevention. TRIAL REGISTRATION: ACTRN12623000344695.


Assuntos
Antimaláricos , Artemisininas , Malária Falciparum , Malária , Piperazinas , Quinolinas , Criança , Adulto , Humanos , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Combinação Arteméter e Lumefantrina/uso terapêutico , Combinação Arteméter e Lumefantrina/farmacologia , Prevalência , Togo/epidemiologia , Estudos Prospectivos , Artemeter/uso terapêutico , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Malária/tratamento farmacológico , Resistência a Medicamentos , Tetra-Hidrofolato Desidrogenase/genética , Biomarcadores , Combinação de Medicamentos , Plasmodium falciparum/genética
16.
Dtsch Med Wochenschr ; 149(8): 454-457, 2024 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-38565119

RESUMO

HISTORY: A 42-year-old female presented with a two-day history of vomiting, diarrhea, fever and chills. Two weeks before she had returned to Germany from a Safari in Tanzania. She had disregarded the recommendation to take antimalarial chemoprophylaxis. CLINICAL FINDINGS AND DIAGNOSIS: The thin blood film showed Plasmodium falciparum-parasitized erythrocytes, and Plasmodium falciparum malaria was diagnosed. The full blood count showed thrombocytopenia and ultrasound imaging revealed splenomegaly. Initially the criteria for complicated malaria were not fulfilled. THERAPY AND COURSE: We started oral therapy with atovaquone/proguanil. The patient vomited the tablets twice. Therefore therapy was switched to intravenous artesunate. Subsequently, parasitemia dropped from 2.8 to 1.0 % within 22 hours. After 3 days of artesunate i. v., treatment could then be completed with oral atovaquone/proguanil, and the symptoms resolved. CONCLUSIONS: Patients with malaria and persistent vomiting should be treated intravenously and monitored closely, as severe gastrointestinal symptoms may reflect impending organ failure. We therefore propose including persistent vomiting in the list of criteria for complicated malaria.


Assuntos
Antimaláricos , Malária Falciparum , Malária , Feminino , Humanos , Adulto , Proguanil/uso terapêutico , Atovaquona/uso terapêutico , Artesunato/uso terapêutico , Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Malária Falciparum/complicações , Malária Falciparum/diagnóstico , Malária Falciparum/tratamento farmacológico , Combinação de Medicamentos , Vômito/etiologia
17.
Malar J ; 23(1): 124, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38678245

RESUMO

BACKGROUND: Malaria contributes to excess child mortality in The Gambia. Children under five are at risk of severe malaria and death if not treated promptly and appropriately. It is crucial that a child with fever receive appropriate care from a trained provider. The aim was to identify influences on child fever care-seeking in The Gambia to inform malaria control strategies. METHODS: This cross-sectional analysis of The Gambia 2019-20 Demographic and Health Survey used logistic regression analysis to identify associations between source of care for a child with fever (public or private healthcare provider, other, or no treatment) and mother, child, and household characteristics. RESULTS: Only 52.0% of mothers sought care from a trained healthcare provider for a child with fever-45.1% from a public facility and 7.0% from the private sector. 35.2% of mothers did not seek treatment. Mothers in urban households were 2.67 times as likely (aOR, 95% CI 1.504-4.736) as mothers in rural households to seek care from an informal source (e.g., pharmacy) versus not seeking treatment, and 0.29 times as likely (aOR, 95% CI 0.165-0.515) as mothers in rural households to seek care from a public provider versus informal source. Mothers in wealthier households were 2.30 times as likely (aOR, 95% CI 1.274-4.164) as mothers in poorer households to seek care from an informal source versus no treatment and half as likely as mothers in poorer households to seek care from a public provider versus informal source (aOR 0.53, 95% CI 0.291-0.959). CONCLUSIONS: Maintaining The Gambia's malaria control achievements will require the active engagement and oversight of private pharmacies along with continued integrated community case management to reach mothers who do not seek care for a child with fever, and remove challenges to seeking appropriate care from trained providers. Whether influenced by convenience, costs, perceived urgency, or other factors, given the likelihood of urban mothers and mothers in wealthier households to seek care from private pharmacies, it will be necessary to incorporate private pharmacies into malaria control strategies while building public sector capacity and workforce, and initiating more effective attitude and behavioural change among mothers and households.


Assuntos
Febre , Aceitação pelo Paciente de Cuidados de Saúde , Humanos , Gâmbia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Estudos Transversais , Feminino , Lactente , Pré-Escolar , Masculino , Adulto , Febre/terapia , Adulto Jovem , Malária/tratamento farmacológico , Adolescente , Pessoa de Meia-Idade , População Rural/estatística & dados numéricos , Recém-Nascido , Mães/estatística & dados numéricos , Mães/psicologia
18.
Malar J ; 23(1): 103, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609987

RESUMO

BACKGROUND: The emergence of resistance to artemisinin-based combination therapy necessitates the search for new, more potent antiplasmodial compounds, including herbal remedies. The whole extract of Maytenus senegalensis has been scientifically investigated for potential biological activities both in vitro and in vivo, demonstrating strong antimalarial activity. However, there is a lack of data on the electrocardiographic effects of M. senegalensis in humans, which is a crucial aspect in the investigation of malaria treatment. Assessing the electrocardiographic effects of M. senegalensis is essential, as many anti-malarial drugs can inadvertently prolong the QT interval on electrocardiograms. Therefore, the study's objective was to evaluate the electrocardiographic effects of M. senegalensis in healthy adult volunteers. METHODS: This study is a secondary analysis of an open-label single-arm dose escalation. Twelve healthy eligible Tanzanian males, aged 18 to 45, were enrolled in four study dose groups. A single 12-lead electrocardiogram (ECG) was performed at baseline and on days 3, 7, 14, 28, and 56. RESULTS: No QTcF adverse events occurred with any drug dose. Only one volunteer who received the highest dose (800 mg) of M. senegalensis experienced a moderate transient change (△QTcF > 30 ms; specifically, the value was 37 ms) from baseline on day 28. There was no difference in maximum QTcF and maximum △QTcF between volunteers in all four study dose groups. CONCLUSIONS: A four-day regimen of 800 mg every 8 h of M. senegalensis did not impact the electrocardiographic parameters in healthy volunteers. This study suggests that M. senegalensis could be a valuable addition to malaria treatment, providing a safer alternative and potentially aiding in the battle against artemisinin-resistant malaria. The results of this study support both the traditional use and the modern therapeutic potential of M. senegalensis. They also set the stage for future research involving larger and more diverse populations to explore the safety profile of M. senegalensis in different demographic groups. This is especially important considering the potential use of M. senegalensis as a therapeutic agent and its widespread utilization as traditional medicine. Trial registration ClinicalTrials.gov, NCT04944966. Registered 30 June 2021-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04944966?term=kamaka&draw=2&rank=1.


Assuntos
Antimaláricos , Artemisininas , Malária , Maytenus , Adulto , Humanos , Masculino , Antimaláricos/farmacologia , Eletrocardiografia , Voluntários Saudáveis , Malária/tratamento farmacológico , Tanzânia , Voluntários , Adulto Jovem , Pessoa de Meia-Idade
19.
Malar J ; 23(1): 93, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575935

RESUMO

BACKGROUND: Plasmodium ovale malaria is usually considered a tropical infectious disease associated with low morbidity and mortality. However, severe disease and death have previously been reported. CASE PRESENTATION: A case of severe P. ovale malaria in a healthy Caucasian man with a triangle splenic infarction and clinical progression towards Acute Respiratory Distress Syndrome was reported despite a rapid response to oral chloroquine treatment with 24-h parasitaemia clearance. CONCLUSION: Plasmodium ovale malaria is generally considered as a benign disease, with low parasitaemia. However, severe disease and death have occasionally been reported. It is important to be aware that occasionally it can progress to serious illness and death even in immunocompetent individuals.


Assuntos
Antimaláricos , Malária , Plasmodium ovale , Síndrome do Desconforto Respiratório , Infarto do Baço , Masculino , Humanos , Antimaláricos/uso terapêutico , Infarto do Baço/diagnóstico , Infarto do Baço/complicações , Infarto do Baço/tratamento farmacológico , Malária/complicações , Malária/diagnóstico , Malária/tratamento farmacológico , Síndrome do Desconforto Respiratório/diagnóstico , Síndrome do Desconforto Respiratório/etiologia , Itália
20.
J Ethnopharmacol ; 330: 118200, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-38621467

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria eradication has been a major goal of the Indonesian government since 2020. Medicinal plants, such as Strychnos lucida R. Br., are empirically used to treat malaria through traditional preparation methods. However, the safety and efficacy of these plants have not yet been confirmed. Therefore, further investigations are necessary to confirm the safety and efficacy of S. lucida as an antimalarial agent. AIMS OF THE STUDY: To quantify the concentration of brucine in the S. lucida extract, determine the acute oral toxicity of the standardized extract, and evaluate the in vivo antimalarial potency of S. lucida tablet (SLT). MATERIALS AND METHODS: Acute oral toxicity of S.lucida extract was determined using the Organization for Economic Co-operation and Development 420 procedure, and the analytical method for brucine quantification was validated using high-performance liquid chromatography. In addition, antimalarial activity was determined using the Peter's four-day suppressive method. RESULTS: Acute toxicity analysis revealed S. lucida as a low-toxicity compound with a cut-off median lethal dose of 2000-5000 mg/kg body weight [BW], which was supported by the hematological and biochemical profiles of the kidneys, liver, and pancreas (p > 0.05). Extract standardization revealed that S. lucida contained 3.91 ± 0.074% w/w brucine, adhering to the limit specified in the Indonesian Herbal Pharmacopeia. Antimalarial test revealed that SLT inhibited the growth of Plasmodium berghei by 27.74-45.27%. Moreover, SLT improved the hemoglobin and hematocrit levels. White blood cell and lymphocyte counts were lower in the SLT-treated group than in the K (+) group (p < 0.05). CONCLUSION: Histopathological and biochemical evaluations revealed that S. lucida extract was safe at a dose of 2000 mg/kg BW with low toxicity. SLT inhibited Plasmodium growth and improved the hemoglobin, hematocrit, and red blood cell profiles. Additionally, SLT reduced the lymphocyte and WBC counts and increased the monocyte and thrombocyte counts as part of the immune system response against Plasmodium infection.


Assuntos
Antimaláricos , Extratos Vegetais , Plasmodium berghei , Strychnos , Comprimidos , Antimaláricos/toxicidade , Antimaláricos/farmacologia , Animais , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Camundongos , Masculino , Strychnos/química , Plasmodium berghei/efeitos dos fármacos , Administração Oral , Estricnina/análogos & derivados , Estricnina/toxicidade , Estricnina/farmacologia , Feminino , Malária/tratamento farmacológico , Testes de Toxicidade Aguda , Dose Letal Mediana
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