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JCI Insight Dec 2019Despite an unprecedented 2 decades of success, the combat against malaria - the mosquito-transmitted disease caused by Plasmodium parasites - is no longer progressing....
Despite an unprecedented 2 decades of success, the combat against malaria - the mosquito-transmitted disease caused by Plasmodium parasites - is no longer progressing. Efforts toward eradication are threatened by the lack of an effective vaccine and a rise in antiparasite drug resistance. Alternative approaches are urgently needed. Repurposing of available, approved drugs with distinct modes of action are being considered as viable and immediate adjuncts to standard antimicrobial treatment. Such strategies may be well suited to the obligatory and clinically silent first phase of Plasmodium infection, where massive parasite replication occurs within hepatocytes in the liver. Here, we report that the widely used antidiabetic drug, metformin, impairs parasite liver stage development of both rodent-infecting Plasmodium berghei and human-infecting P. falciparum parasites. Prophylactic treatment with metformin curtails parasite intracellular growth in vitro. An additional effect was observed in mice with a decrease in the numbers of infected hepatocytes. Moreover, metformin provided in combination with conventional liver- or blood-acting antimalarial drugs further reduced the total burden of P. berghei infection and substantially lessened disease severity in mice. Together, our findings indicate that repurposing of metformin in a prophylactic regimen could be considered for malaria chemoprevention.
Topics: Animals; Antimalarials; Cells, Cultured; Disease Models, Animal; Drug Evaluation, Preclinical; Drug Repositioning; Drug Therapy, Combination; Hepatocytes; Humans; Inhibitory Concentration 50; Liver; Malaria; Male; Mefloquine; Metformin; Mice; Parasite Load; Parasitic Sensitivity Tests; Plasmodium berghei; Plasmodium falciparum; Primaquine; Primary Cell Culture
PubMed: 31852843
DOI: 10.1172/jci.insight.127441 -
International Journal of Antimicrobial... Apr 2021Infections caused by carbapenem-resistant Enterobacterales are difficult to treat. Colistin is the last-resort drug for the treatment of these infections, however...
Infections caused by carbapenem-resistant Enterobacterales are difficult to treat. Colistin is the last-resort drug for the treatment of these infections, however colistin resistance has emerged in animals and humans. This study investigated the in vitro efficacy of mefloquine in combination with colistin against 114 antibiotic-resistant Enterobacterales isolates including NDM-1, extended-spectrum β-lactamase (ESBL) and mcr-1 containing strains from a broad range of origins. The effect of the mefloquine and colistin combination was examined in vitro by chequerboard method and time-kill analysis and in vivo in a murine peritoneal infection model. The fractional inhibitory concentration index (FICI) of the combination indicated that synergy was detected for all NDM-1 and mcr-1 containing strains, 87.5% of ESBL producing Escherichia coli and 97.9% of ESBL producing Klebsiella pneumoniae strains. Time-kill curves demonstrated significant synergistic activity with low concentrations of colistin that were boosted by mefloquine. The combination showed enhanced activity against infection with NDM-1- or mcr-1 containing Enterobacteriaceae in mice at 4 h and 6 h after treatment. These findings suggest that the combination of mefloquine and colistin has the potential for rejuvenating the activity of colistin against multidrug-resistant Enterobacterales.
Topics: Animals; Anti-Bacterial Agents; Carbapenem-Resistant Enterobacteriaceae; Colistin; Drug Resistance, Multiple, Bacterial; Drug Synergism; Drug Therapy, Combination; Escherichia coli; Female; Klebsiella pneumoniae; Mefloquine; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; beta-Lactamases
PubMed: 33609719
DOI: 10.1016/j.ijantimicag.2021.106309 -
Patient Preference and Adherence 2020Chemoprophylaxis is an effective tool for individuals to minimize their risk of contracting malaria and serves an important public health role in preventing imported... (Review)
Review
BACKGROUND
Chemoprophylaxis is an effective tool for individuals to minimize their risk of contracting malaria and serves an important public health role in preventing imported malaria. Yet, it is only effective if the traveller is fully compliant with the prescribed regimen. For many destinations, a choice of prophylactic agents is available, so historical compliance data can be helpful for both physicians and travellers to make an informed decision.
METHODS
We analyzed the historical self-reported compliance data for six chemoprophylactic agents currently recommended by CDC for primary malaria chemoprophylaxis by searching PubMed, Embase, CINAHL, Web of Science, and Scopus for observational studies reporting on travelers within the last 25 years. The quality of data was graded as "good" or "poor" using the NIH quality assessment tool for cohort and cross-sectional studies. Cumulative compliance data were compiled for all studies (gross compliance) and the subgroup of studies with "good" quality evidence (refined compliance). Subgroup analyses were performed for weekly vs daily administered regimens, between military and civilian travelers, and across each prophylactic agent.
RESULTS
Twenty-four eligible studies assessed compliance for mefloquine (n=20), atovaquone-proguanil (n=11), doxycycline (n=13), and chloroquine (n=3). No studies were found for primaquine or tafenoquine. Both gross and refined compliance were significantly better for weekly regimens than daily regimens (<0.0001). Stopping chemoprophylaxis due to adverse events was significantly more for doxycycline (<0.0001) compared to other drugs. Compliance was significantly worse in military travelers, but they were also more likely to be prescribed doxycycline.
CONCLUSION
Malaria chemoprophylaxis for a traveler should depend on prevailing resistance patterns at destination, current national guidelines, and patient preferences. However, when there is a choice, historical compliance data are useful to select a regimen that the traveler is more likely to comply with.
PubMed: 33204072
DOI: 10.2147/PPA.S255561 -
Travel Medicine and Infectious Disease 2023Hair analysis to identify substance use is an established methodology. This could also be a method to monitor adherence to antimalarial drugs. We aimed to establish a...
BACKGROUND
Hair analysis to identify substance use is an established methodology. This could also be a method to monitor adherence to antimalarial drugs. We aimed to establish a methodology to determine hair concentrations of atovaquone, proguanil and mefloquine in travellers using chemoprophylaxis.
METHODS
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous analysis of the antimalarial drugs -atovaquone (ATQ), proguanil (PRO) and mefloquine (MQ), in human hair. The hair samples from five volunteers were used for this proof-of-concept analysis. Three volunteers were taking daily atovaquone/proguanil (ATQ/PRO) chemoprophylaxis and two volunteers were using weekly mefloquine (MQ) chemoprophylaxis.
RESULTS
With this proof-of-principle analysis, we could show that ATQ/PRO and MQ are integrated into the hair matrix. Chemoprophylaxis could be quantified with the established method. In hair segments, maximal concentrations of 3.0 ng/mL/20 mg hair proguanil, 1.3 ng/mL/20 mg hair atovaquone and 78.3 ng/mL/20 mg hair mefloquine were measured. Moreover, malaria drug concentration changes correlated with the time interval since finishing the chemoprophylaxis regimen.
CONCLUSIONS
The validated method was used successfully for the analysis of antimalarial-drug positive hair samples containing atovaquone, proguanil or mefloquine. This research shows that hair can be used for adherence monitoring of chemoprophylaxis and paves the way for larger studies and optimized procedures.
Topics: Humans; Antimalarials; Proguanil; Atovaquone; Mefloquine; Chromatography, Liquid; Drug Therapy, Combination; Travel; Tandem Mass Spectrometry; Drug Combinations
PubMed: 37209974
DOI: 10.1016/j.tmaid.2023.102590 -
Pharmacological Research Aug 2019Malaria affects 200 million people worldwide. Today, the most successful treatments are artemisinin-based combination therapies (ACT). Resistance has already been...
Malaria affects 200 million people worldwide. Today, the most successful treatments are artemisinin-based combination therapies (ACT). Resistance has already been described for the elder anti-malarials chloroquine, sulfadoxine-pyrimethamine and mefloquine. Unfortunately, over the last few years there has also been an emerging resistance to the successfully used drug artemisinin, especially in African and Asian countries. A systematic PubMed literature research was conducted for studies published between January 2002 and December 2018. Despite ACTs continue to be first line treatment, the number of studies is rising reporting on artemisinin resistance mutations. Most publications reported on kelch13 mutations (45 studies), the second most frequent mutations were found in pfmdr1 (32 studies). PfATPase6 mutations have been mainly studied in Asian countries (4 of 6 studies). Bearing this in mind, there is a pressing need to further examine the role and spread of mutations conferring artemisinin resistance. A further decline of treatment efficacy could result in increased rates of malaria-related deaths.
Topics: Animals; Antimalarials; Artemisinins; Drug Resistance; Humans; Malaria; Mutation; Polymorphism, Genetic
PubMed: 31100335
DOI: 10.1016/j.phrs.2019.104275 -
Current Research in Pharmacology and... 2024infection is a health challenge. Although, antiplasmodial drugs kill the parasites, information on the effects of infection and drugs on the expression of some genes is...
infection is a health challenge. Although, antiplasmodial drugs kill the parasites, information on the effects of infection and drugs on the expression of some genes is limited. Malaria was induced in two different studies using NK65 (chloroquine-susceptible, study 1), and ANKA (chloroquine-resistant, study 2) strains of in 30 male Swiss mice (n = 5) in each study. Mice orally received 10 mL/kg distilled water, (infected control), Mefloquine (MF) (10 mg/kg), MF and Curcumin (CM) (25 mg/kg), MF and CM (50 mg/kg), CM (25 mg/kg) and CM (50 mg/kg). Five mice (un-infected) were used as the control. After treatment, total Ribonucleic acid (RNA) was isolated from liver and erythrocytes while Deoxyribonucleic acid (DNA)-free RNA were converted to cDNA. Polymerase Chain Reaction (PCR) amplification was performed and relative expressions of oxidoreductase, and cytochrome oxidase expressions were determined. Markers of glycolysis, toxicity and antioxidants were determined using ELISA assays. While the expression of was blunted by MF in the susceptible study, co-treatment with curcumin (25 mg/kg) yielded the same results in the chloroquine-resistant study. Similar results were obtained on in both studies. Curcumin decreased in both studies. infection decreased oxidoreductase and cytochrome oxidase but mefloquine-curcumin restored the expression of these genes. While glycolysis and toxicity were inhibited, antioxidant systems improved in the treated groups. Curcumin is needed for effective therapeutic efficacy and prevention of toxicity. infection and treatment modulate the expressions of some genes in the host. Curcumin combination with mefloquine modulates the expression of some genes in the host.
PubMed: 38725654
DOI: 10.1016/j.crphar.2024.100180 -
Clinical Pharmacokinetics Oct 2020Although the separate effects of drug-drug interactions and pregnancy on antiretroviral drug pharmacokinetics have been widely studied and described, their combined... (Review)
Review
BACKGROUND AND OBJECTIVE
Although the separate effects of drug-drug interactions and pregnancy on antiretroviral drug pharmacokinetics have been widely studied and described, their combined effect is largely unknown. Physiological changes during pregnancy may change the extent or clinical relevance of a drug-drug interaction in a pregnant woman. This review aims to provide a detailed overview of the mechanisms, magnitude, and clinical significance of antiretroviral drug-drug interactions in pregnant women.
METHODS
We performed a literature search and selected studies that compared the magnitude of drug-drug interactions with antiretroviral drugs in pregnant vs non-pregnant women.
RESULTS
Forty-eight papers examining drug-drug interactions during pregnancy were selected, of which the majority focused on pharmacokinetic boosting. Other selected studies examined the drug-drug interactions between efavirenz and lumefantrine, efavirenz and tuberculosis drugs, etravirine and tenofovir disoproxil fumarate, atazanavir and tenofovir disoproxil, and mefloquine and nevirapine in pregnant compared to non-pregnant women. The clinical significance of antiretroviral drug-drug interactions changed during pregnancy from a minimal effect to a contra-indication. In almost all cases, the clinical significance of a drug-drug interaction was more relevant in pregnant women, owing to the combined effects of pregnancy-induced physiological changes and drug-drug interactions leading to a lower absolute drug exposure.
CONCLUSIONS
Multiple studies show that the clinical relevance of a drug-drug interaction can change during pregnancy. Unfortunately, many potential interactions have not been studied in pregnancy, which may place pregnant women living with human immunodeficiency virus and their newborns at risk.
Topics: Anti-HIV Agents; Drug Interactions; Female; HIV Infections; Humans; Pregnancy; Pregnant Women
PubMed: 32696442
DOI: 10.1007/s40262-020-00914-x -
Antimicrobial Agents and Chemotherapy Nov 2021Increasing resistance in Plasmodium falciparum to artemisinins and their artemisinin combination therapy (ACT) partner drugs jeopardizes effective antimalarial...
Increasing resistance in Plasmodium falciparum to artemisinins and their artemisinin combination therapy (ACT) partner drugs jeopardizes effective antimalarial treatment. Resistance is worst in the Greater Mekong subregion. Monitoring genetic markers of resistance can help to guide antimalarial therapy. Markers of resistance to artemisinins ( mutations), mefloquine (amplification of P. falciparum multidrug resistance-1 []), and piperaquine ( amplification and specific P. falciparum chloroquine resistance transporter [] mutations) were assessed in 6,722 P. falciparum samples from Vietnam, Lao People's Democratic Republic (PDR), Cambodia, Thailand, and Myanmar between 2007 and 2019. Against a high background prevalence of mutations, and amplification closely followed regional drug pressures over time. amplification preceded piperaquine resistance-associated mutations in Cambodia and reached a peak prevalence of 23/28 (82%) in 2015. This declined to 57/156 (38%) after first-line treatment was changed from dihydroartemisinin-piperaquine to artesunate-mefloquine (ASMQ) between 2014 and 2017. The frequency of amplification increased from 0/293 (0%) between 2012 and 2017 to 12/156 (8%) in 2019. Amplification of and in the same parasites was extremely rare (4/6,722 [0.06%]) and was dispersed over time. The mechanisms conferring mefloquine and piperaquine resistance may be counterbalancing. This supports the development of ASMQ plus piperaquine as a triple artemisinin combination therapy.
Topics: Antimalarials; Drug Resistance; Drug Resistance, Multiple; Genetic Markers; Humans; Longitudinal Studies; Malaria, Falciparum; Multidrug Resistance-Associated Proteins; Plasmodium falciparum; Protozoan Proteins
PubMed: 34516247
DOI: 10.1128/AAC.01121-21 -
Antimicrobial Agents and Chemotherapy May 2024Capillary samples offer practical benefits compared with venous samples for the measurement of drug concentrations, but the relationship between the two measures varies... (Comparative Study)
Comparative Study
Comparison of lumefantrine, mefloquine, and piperaquine concentrations between capillary plasma and venous plasma samples in pregnant women with uncomplicated falciparum and vivax malaria.
Capillary samples offer practical benefits compared with venous samples for the measurement of drug concentrations, but the relationship between the two measures varies between different drugs. We measured the concentrations of lumefantrine, mefloquine, piperaquine in 270 pairs of venous plasma and concurrent capillary plasma samples collected from 270 pregnant women with uncomplicated falciparum or vivax malaria. The median and range of venous plasma concentrations included in this study were 447.5 ng/mL (8.81-3,370) for lumefantrine (day 7, = 76, median total dose received 96.0 mg/kg), 17.9 ng/mL (1.72-181) for desbutyl-lumefantrine, 1,885 ng/mL (762-4,830) for mefloquine (days 3-21, = 90, median total dose 24.9 mg/kg), 641 ng/mL (79.9-1,950) for carboxy-mefloquine, and 51.8 ng/mL (3.57-851) for piperaquine (days 3-21, = 89, median total dose 52.2 mg/kg). Although venous and capillary plasma concentrations showed a high correlation (Pearson's correlation coefficient: 0.90-0.99) for all antimalarials and their primary metabolites, they were not directly interchangeable. Using the concurrent capillary plasma concentrations and other variables, the proportions of venous plasma samples predicted within a ±10% precision range was 34% (26/76) for lumefantrine, 36% (32/89) for desbutyl-lumefantrine, 74% (67/90) for mefloquine, 82% (74/90) for carboxy-mefloquine, and 24% (21/89) for piperaquine. Venous plasma concentrations of mefloquine, but not lumefantrine and piperaquine, could be predicted by capillary plasma samples with an acceptable level of agreement. Capillary plasma samples can be utilized for pharmacokinetic and clinical studies, but caution surrounding cut-off values is required at the individual level.CLINICAL TRIALSThis study is registered with ClinicalTrials.gov as NCT01054248.
Topics: Humans; Female; Mefloquine; Antimalarials; Pregnancy; Quinolines; Lumefantrine; Malaria, Falciparum; Adult; Malaria, Vivax; Young Adult; Ethanolamines; Fluorenes; Adolescent; Piperazines
PubMed: 38597636
DOI: 10.1128/aac.00093-24 -
International Journal For Parasitology.... Apr 2023Alveolar echinococcosis (AE) is caused by infection with the fox tapeworm E. multilocularis. The disease affects humans, dogs, captive monkeys, and other mammals, and it...
Alveolar echinococcosis (AE) is caused by infection with the fox tapeworm E. multilocularis. The disease affects humans, dogs, captive monkeys, and other mammals, and it is caused by the metacestode stage of the parasite growing invasively in the liver. The current drug treatment is based on non-parasiticidal benzimidazoles. Thus, they are only limitedly curative and can cause severe side effects. Therefore, novel and improved treatment options for AE are needed. Mefloquine (MEF), an antimalarial agent, was previously shown to be effective against E. multilocularis in vitro and in experimentally infected mice. However, MEF is not parasiticidal and needs improvement for successful treatment of patients, and it can induce strong neuropsychiatric side-effects. In this study, the structure-activity relationship and mode of action of MEF was investigated by comparative analysis of 14 MEF derivatives. None of them showed higher activity against E. multilocularis metacestodes compared to MEF, but four compounds caused limited damage. In order to identify molecular targets of MEF and effective derivatives, differential affinity chromatography combined with mass spectrometry was performed with two effective compounds (MEF, MEF-3) and two ineffective compounds (MEF-13, MEF-22). 1'681 proteins were identified that bound specifically to MEF or derivatives. 216 proteins were identified as binding only to MEF and MEF-3. GO term enrichment analysis of these proteins and functional grouping of the 25 most abundant MEF and MEF-3 specific binding proteins revealed the key processes energy metabolism and cellular transport and structure, as well as stress responses and nucleic acid binding to be involved. The previously described ferritin was confirmed as an exclusively MEF-binding protein that could be relevant for its efficacy against E. multilocularis. The here identified potential targets of MEF will be further investigated in the future for a clear understanding of the pleiotropic effects of MEF, and improved therapeutic options against AE.
Topics: Humans; Mice; Animals; Dogs; Mefloquine; Echinococcus multilocularis; Parasites; Echinococcosis; Antiparasitic Agents; Mammals
PubMed: 36921443
DOI: 10.1016/j.ijpddr.2023.03.002