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1.
Malar J ; 20(1): 62, 2021 Jan 23.
Article in English | MEDLINE | ID: mdl-33485330

ABSTRACT

BACKGROUND: Malaria caused by Plasmodium falciparum in pregnancy can result in adverse maternal and fetal sequelae. This review evaluated the adherence of the national guidelines drawn from World Health Organization (WHO) regions, Africa, Eastern Mediterranean, Southeast Asia, and Western Pacific, to the WHO recommendations on drug treatment and prevention of chloroquine-resistant falciparum malaria in pregnant women. METHODS: Thirty-five updated national guidelines and the President's Malaria Initiative (PMI), available in English language, were reviewed. The primary outcome measures were the first-line anti-malarial treatment protocols adopted by national guidelines for uncomplicated and complicated falciparum malaria infections in early (first) and late (second and third) trimesters of pregnancy. The strategy of intermittent preventive treatment of malaria in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) was also addressed. RESULTS: This review evaluated the treatment and prevention of falciparum malaria in pregnancy in 35 national guidelines/PMI-Malaria Operational Plans (MOP) reports out of 95 malaria-endemic countries. Of the 35 national guidelines, 10 (28.6%) recommend oral quinine plus clindamycin as first-line treatment for uncomplicated malaria in the first trimester. As the first-line option, artemether-lumefantrine, an artemisinin-based combination therapy, is adopted by 26 (74.3%) of the guidelines for treating uncomplicated or complicated malaria in the second and third trimesters. Intravenous artesunate is approved by 18 (51.4%) and 31 (88.6%) guidelines for treating complicated malaria during early and late pregnancy, respectively. Of the 23 national guidelines that recommend IPTp-SP strategy, 8 (34.8%) are not explicit about directly observed therapy requirements, and three-quarters, 17 (73.9%), do not specify contra-indication of SP in human immunodeficiency virus (HIV)-infected pregnant women receiving cotrimoxazole prophylaxis. Most of the guidelines (18/23; 78.3%) state the recommended folic acid dose. CONCLUSION: Several national guidelines and PMI reports require update revisions to harmonize with international guidelines and emergent trends in managing falciparum malaria in pregnancy. National guidelines and those of donor agencies should comply with those of WHO guideline recommendations although local conditions and delayed guideline updates may call for deviations from WHO evidence-based guidelines.


Subject(s)
Antimalarials/therapeutic use , Malaria/drug therapy , Malaria/prevention & control , Practice Guidelines as Topic/standards , Pregnancy Complications, Parasitic/prevention & control , Adult , Antimalarials/classification , Artemether/therapeutic use , Artemether, Lumefantrine Drug Combination/therapeutic use , Artesunate/therapeutic use , Chloroquine/therapeutic use , Drug Combinations , Female , Humans , Parasitemia/drug therapy , Pregnancy , Pyrimethamine/therapeutic use , Quinine/therapeutic use , Sulfadoxine/therapeutic use
2.
Exp Parasitol ; 219: 108011, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33010286

ABSTRACT

A hallmark of mortality and morbidity, malaria is affecting nearly half of the world's population. Emergence of drug-resistant strains of malarial parasite prompts identification and evaluation of medicinal plants and their constituents that may hold the key to a new and effective anti-malarial drug. In this context, nineteen methanolic extracts from seventeen medicinal plants were evaluated for anti-plasmodial potential against Plasmodium falciparum strain 3D7 (Chloroquine (CQ) sensitive) and INDO (CQ resistant) using fluorescence based SYBR-Green assay and for cytotoxic effects against mammalian cell lines. Leaf extract of two plants showed promising in vitro anti-malarial activity (Pf3D7 IC50 ≤ 10 µg/ml); one plant extract showed good activity (Pf3D7 IC50 = 10.1-20 µg/ml); seven were moderately active (IC50 = 20.1-50 µg/ml), four plant extracts showed poor activity (PfD7 IC50 = 50.1-100 µg/ml) and five extracts showed no activity up to IC50 = 100 µg/ml. Further, six extracts were found equipotent to PfINDO (resistance index ranging 0.4-2) and relatively nontoxic to mammalian cell lines HEK293 (cytotoxicity index ranging 1.4-12.5). Based on good resistance and selectivity indices, three extracts were evaluated for in vivo activity in Plasmodium berghei ANKA infected mice at a dose of 500 mg/kg and they showed significant suppression of P. berghei parasitemia. Further, these active plant extracts were fractionated using silica-gel chromatography and their fractions were evaluated for anti-plasmodial action. Obtained fractions showed enrichment in antimalarial activity. Active fractions were analyzed by gas chromatography and mass-spectrometery. Results suggests that the three active plant extracts could serve as potent source of anti-malarial agent and therefore require further analysis.


Subject(s)
Antimalarials/pharmacology , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Plasmodium berghei/drug effects , Plasmodium falciparum/drug effects , Acacia/chemistry , Animals , Antimalarials/classification , Antimalarials/toxicity , Chromatography, High Pressure Liquid , Dose-Response Relationship, Drug , Ethnopharmacology , Female , Gas Chromatography-Mass Spectrometry , HEK293 Cells , Humans , India , Inhibitory Concentration 50 , Medicine, East Asian Traditional , Mice , Mice, Inbred BALB C , Plant Extracts/toxicity , Plant Leaves/chemistry , Plants, Medicinal/classification , Rubus/chemistry , Syzygium/chemistry
3.
Malar J ; 18(1): 133, 2019 Apr 11.
Article in English | MEDLINE | ID: mdl-30975147

ABSTRACT

BACKGROUND: In 2006, artemether-lumefantrine (ALU), specifically Coartem® (Novartis Pharma AG, Basel Switzerland), was approved as the first-line drug for treatment of uncomplicated malaria in Tanzania. Due to poor availability and affordability of the innovator's product, the government of Tanzania in 2013 prequalified the use of generic anti-malarial drugs, whereby Artefan® (Ajanta, Pharma Ltd, India) was the first to be approved. METHODS: This was an equivalence prospective study that aimed to determine the effectiveness of anti-malarial generic Artefan® in comparison with innovator's product Coartem®. Patients aged 6 to 59 months with uncomplicated malaria were recruited and randomized to either receive Artefan® or Coartem® as a control. Participants were required to revisit clinic five times as follow up to monitor treatment outcome as per World Health Organization recommendations. On each visit, thick and thin blood smears, dried blood spot (DBS), haemoglobin concentrations and auxiliary temperature were performed and documented. RESULTS: Out of 230 recruited participants, 200 met inclusion criteria and were randomized equally to receive Artefan® and Coartem®. The overall PCR uncorrected cure rate were 80% for Artefan® and 75% for Coartem® (p = 0.44). Adequate clinical and parasitological response were 82.1% for Artefan® and 74.7% for Coartem®, and there was no early treatment failure (ETF) observed in both arms of treatment. Both drugs showed excellent early parasite clearance, whereby no participants had peripheral parasitaemia on day 3. Late clinical failures (LCF) were 3.6% for Artefan® and 1.3% for Coartem® (p = 0.31), and late parasitological failure (LPF) were 15.4% for Artefan® and 22.7% for Coartem® (p = 0.32). Mean haemoglobin (g/dl) concentrations observed on day 28 were higher compared to day 0 for both drugs, although not statistically significant. Only one (1.3%) participant on Artefan® had temperature ≥ 37.5 °C on day 3. CONCLUSION: The findings of this study indicate that both Artefan® and Coartem® are equivalent and effective in the management of uncomplicated malaria amongst children in the Coast part of Tanzania.


Subject(s)
Antimalarials/therapeutic use , Artemether, Lumefantrine Drug Combination/therapeutic use , Malaria, Falciparum/drug therapy , Malaria/drug therapy , Antimalarials/classification , Artemether, Lumefantrine Drug Combination/classification , Child, Preschool , Drugs, Generic/classification , Drugs, Generic/pharmacology , Equivalence Trials as Topic , Female , Humans , Infant , Male , Prospective Studies , Tanzania , Treatment Outcome
5.
Malar J ; 16(1): 57, 2017 01 31.
Article in English | MEDLINE | ID: mdl-28143519

ABSTRACT

BACKGROUND: Malaria remains one of the most serious infections for travellers to tropical countries. Due to the lack of harmonized guidelines a large variety of treatment regimens is used in Europe to treat severe malaria. METHODS: The European Network for Tropical Medicine and Travel Health (TropNet) conducted an 8-year, multicentre, observational study to analyse epidemiology, treatment practices and outcomes of severe malaria in its member sites across Europe. Physicians at participating TropNet centres were asked to report pseudonymized retrospective data from all patients treated at their centre for microscopically confirmed severe Plasmodium falciparum malaria according to the 2006 WHO criteria. RESULTS: From 2006 to 2014 a total of 185 patients with severe malaria treated in 12 European countries were included. Three patients died, resulting in a 28-day survival rate of 98.4%. The majority of infections were acquired in West Africa (109/185, 59%). The proportion of patients treated with intravenous artesunate increased from 27% in 2006 to 60% in 2013. Altogether, 56 different combinations of intravenous and oral drugs were used across 28 study centres. The risk of acute renal failure (36 vs 17% p = 0.04) or cerebral malaria (54 vs 20%, p = 0.001) was significantly higher in patients ≥60 years than in younger patients. Respiratory distress with the need for mechanical ventilation was significantly associated with the risk of death in the study population (13 vs 0%, p = 0.001). Post-artemisinin delayed haemolysis was reported in 19/70 (27%) patients treated with intravenous artesunate. CONCLUSION: The majority of patients with severe malaria in this study were tourists or migrants acquiring the infection in West Africa. Intravenous artesunate is increasingly used for treatment of severe malaria in many European treatment centres and can be given safely to European patients with severe malaria. Patients treated with intravenous artesunate should be followed up to detect and manage late haemolytic events.


Subject(s)
Antimalarials/therapeutic use , Malaria, Falciparum/drug therapy , Malaria, Falciparum/epidemiology , Adult , Aged , Antimalarials/classification , Europe/epidemiology , Female , Humans , Male , Middle Aged , Treatment Outcome , Young Adult
6.
BMC Med ; 13: 193, 2015 Aug 14.
Article in English | MEDLINE | ID: mdl-26275820

ABSTRACT

BACKGROUND: It is known that antimalarial drugs reduce the risk of low birth weight (LBW) in pregnant patients. However, a previous Cochrane review did not evaluate whether the level of antimalarial drug resistance could modify the protective effect of antimalarial drugs in this regard. In addition, no systematic review exists comparing current recommendations for malaria prevention during pregnancy to alternative regimens in Africa. Therefore, we conducted a comprehensive systematic review and meta-analysis to assess the efficacy of antimalarial drugs for malaria prevention during pregnancy in reducing the risk of LBW. METHODS: We searched PubMed, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) for articles published up to 21 November 2014, in English or French, and identified additional studies from reference lists. We included randomized and quasi-randomized studies reporting LBW as one of the outcomes. We extracted data and assessed the risk of bias in selected studies. All pooled analyses were based on a random effect model, and we used a funnel plot and trim and fill method to test and adjust for publication bias. RESULTS: A total of 25 studies met the inclusion criteria (37,981 subjects). Compared to no use, all combined antimalarial drugs were associated with a 27% (RR 0.73, 95% CI 0.56-0.97, ten studies) reduction in the risk of LBW. The level of antimalarial drug resistance modified the protective effect of the antimalarial drug used for prevention of LBW during pregnancy. Sulfadoxine-pyrimethamine was not associated with a reduction in the risk of LBW in regions where the prevalence of the dihydropteroate synthase 540E mutation exceeds 50% (RR 0.99, 95% CI 0.80-1.22, three studies). The risk of LBW was similar when sulfadoxine-pyrimethamine was compared to mefloquine (RR 1.05, 95% CI 0.86-1.29, two studies). CONCLUSION: Prophylactic antimalarial drugs and specifically sulfadoxine-pyrimethamine may no longer protect against the risk of LBW in areas of high-level resistance. In Africa, there are currently no suitable alternative drugs to replace sulfadoxine-pyrimethamine for malaria prevention during pregnancy.


Subject(s)
Antimalarials/adverse effects , Infant, Low Birth Weight , Malaria , Africa/epidemiology , Antimalarials/administration & dosage , Antimalarials/classification , Drug Resistance , Female , Humans , Infant, Newborn , Malaria/epidemiology , Malaria/prevention & control , Pregnancy , Randomized Controlled Trials as Topic
7.
Med Parazitol (Mosk) ; (3): 51-7, 2014.
Article in Russian | MEDLINE | ID: mdl-25286554

ABSTRACT

The review presents the results of trials of the clinical efficacy of a test antimalarial drug for each malarial parasite species, which were published in 2000-2013 and supplemented by the data of in vitro studies or investigations using the molecular markers of resistance. There are data on the resistance of each medicament since many of the drugs are used in combination with artermisinin derivatives.


Subject(s)
Antimalarials/therapeutic use , Drug Resistance/genetics , Malaria, Falciparum/drug therapy , Malaria, Vivax/drug therapy , Protozoan Proteins/genetics , Antimalarials/chemistry , Antimalarials/classification , Drug Resistance/drug effects , Drug Therapy, Combination , Humans , Mutation , Plasmodium falciparum/drug effects , Plasmodium falciparum/genetics , Plasmodium vivax/drug effects , Plasmodium vivax/genetics
9.
Bioanalysis ; 5(17): 2171-86, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23962252

ABSTRACT

Malaria is the leading parasitic disease in emerging countries. Therapeutic drug monitoring of antimalarial drugs is becoming increasingly important due to their spreading resistance. Measuring systemic antimalarial drug concentrations is also vital for safety and PK evaluations during clinical development. The dried blood spot (DBS) technique is a convenient alternative sample-collection method to venipuncture, especially in resource -limited areas where the clinical studies of antimalarials are usually carried out. Various bioanalytical methods for antimalarial drug estimation utilizing DBS sampling have been reported. This review discusses the applicability and relevance of DBS in quantitative assessment of antimalarial drugs, the advantages and drawbacks of DBS, and the difficulties encountered during its implementation.


Subject(s)
Antimalarials/blood , Dried Blood Spot Testing/standards , Drug Monitoring , Malaria/blood , Antimalarials/classification , Antimalarials/therapeutic use , Blood Specimen Collection/methods , Chromatography, Liquid , Dried Blood Spot Testing/statistics & numerical data , Drug Stability , Hematocrit , Humans , Malaria/drug therapy , Sensitivity and Specificity , Solid Phase Microextraction , Solvents , Tandem Mass Spectrometry
10.
Mol Divers ; 17(3): 489-97, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23653283

ABSTRACT

Plasmodium falciparum glucose-6-phosphate dehydrogenase (PfG6PD) has been considered as a potential target for severe forms of anti-malaria therapy. In this study, several classification models were built to distinguish active and weakly active PfG6PD inhibitors by support vector machine method. Each molecule was initially represented by 1,044 molecular descriptors calculated by ADRIANA.Code. Correlation analysis and attribute selection methods in Weka were used to get the best reduced set of molecular descriptors, respectively. The best model (Model 2w) gave a prediction accuracy (Q) of 93.88 % and a Matthew's correlation coefficient (MCC) of 0.88 on the test set. Some properties such as [Formula: see text] atom charge, [Formula: see text] atom charge, and lone pair electronegativity-related descriptors are important for the interaction between the PfG6PD and the inhibitor.


Subject(s)
Antimalarials/classification , Enzyme Inhibitors/classification , Glucosephosphate Dehydrogenase/antagonists & inhibitors , Plasmodium falciparum/drug effects , Plasmodium falciparum/enzymology , Support Vector Machine , Antimalarials/chemistry , Antimalarials/pharmacology , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Glucosephosphate Dehydrogenase/classification , Malaria, Falciparum/drug therapy
11.
PLoS One ; 8(12): e82962, 2013.
Article in English | MEDLINE | ID: mdl-24391728

ABSTRACT

We have tested five distinct classes of established and experimental antimalarial drugs for their anticancer potential, using a panel of 91 human cancer lines. Three classes of drugs: artemisinins, synthetic peroxides and DHFR (dihydrofolate reductase) inhibitors effected potent inhibition of proliferation with IC50s in the nM- low µM range, whereas a DHODH (dihydroorotate dehydrogenase) and a putative kinase inhibitor displayed no activity. Furthermore, significant synergies were identified with erlotinib, imatinib, cisplatin, dasatinib and vincristine. Cluster analysis of the antimalarials based on their differential inhibition of the various cancer lines clearly segregated the synthetic peroxides OZ277 and OZ439 from the artemisinin cluster that included artesunate, dihydroartemisinin and artemisone, and from the DHFR inhibitors pyrimethamine and P218 (a parasite DHFR inhibitor), emphasizing their shared mode of action. In order to further understand the basis of the selectivity of these compounds against different cancers, microarray-based gene expression data for 85 of the used cell lines were generated. For each compound, distinct sets of genes were identified whose expression significantly correlated with compound sensitivity. Several of the antimalarials tested in this study have well-established and excellent safety profiles with a plasma exposure, when conservatively used in malaria, that is well above the IC50s that we identified in this study. Given their unique mode of action and potential for unique synergies with established anticancer drugs, our results provide a strong basis to further explore the potential application of these compounds in cancer in pre-clinical or and clinical settings.


Subject(s)
Antimalarials/classification , Antimalarials/pharmacology , Antineoplastic Agents/pharmacology , Antimalarials/administration & dosage , Antineoplastic Agents/administration & dosage , Artemisinins/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Cluster Analysis , Drug Screening Assays, Antitumor , Drug Synergism , Folic Acid Antagonists/pharmacology , Gene Expression/drug effects , Humans , Peroxides/pharmacology
12.
Article in Chinese | MEDLINE | ID: mdl-24812850

ABSTRACT

OBJECTIVE: To observe and compare the inhibition of hemozoin formation and the in vitro as well as in vivo antischistosomal activity induced by seven antimalarial drugs. METHODS: Inhibition of hemozoin formation displayed by chloroquine phosphate, quinine hydrochloride, quinidine, mefloquine hydrochloride, pyronaridine phosphate and lumefantrine at 25 micromol/L, and artemether at 100 micromol/L was performed by assay of inhibition of beta-hematin formation in 1 mol/L sodium acetate buffers containing hematin with various pH of 4.0, 4.2, 4.4, 4.6, 4.8, and 5.0. In in vitro antischistosomal study, the medium of RPMI 1640 supplemented by 10% calf serum was used to maintain the adult Schistosoma japonicum, and the 50% and 95% lethal concentrations (LC50 and LC95) to kill the adult worms of each drug were then determined. Meanwhile, the interaction of quinine, pyronaridine and chloroquine combined with hemin against adult schistosomes was also undertaken. As to in vivo test, the efficacy of seven antimalarial drugs administered orally or intraperitoneally to mice infected with adult schistosomes was observed. RESULTS: In the acidic acetate-hematin solution, 25 micromol/L pyronaridine showed significant inhibition of beta-hematin formation at pH 4.4-5.0 with inhibition rates of 81.3%-97.0%. At pH 4.6, the inhibition rates of beta-hematin formation in acetate-hematin solution induced by mefloquine, chloroquine or quinine at concentration of 25 beta mol/L were 79.7%, 72.8% or 65.8%, respectively, and the beta-hematin formation was continually inhibited by these 3 antimalarial drugs at pH 4.8 and 5.0 with inhibition rates of 83.1%-90.6%, 41.9%-49.0% or 53.2-62.0%. The inhibition rates of beta-hematin formation at pH 4.6 and 4.8-5.0 induced by lumefantrine 25 micromol/L were 74.3% and 40.4%-40.5%, respectively. While under the same concentration of quinidine, 53.4% and 50.9% inhibition rates of beta-hematin formation were observed at pH 4.8 and 5.0. As to artemether, higher concentration of 100 micromol/L only showed light inhibition of beta-hematin formation at pH 4.4-4.8 with inhibition rates of 16.6%-25.0%. As regard to in vitro test, the LC50 and LC95 of mefloquine, pyronaridine, quinine and quinidine were 4.93 and 6.123 microg/ml, 37.278 and 75.703 microg/ml, 93.688 and 134.578 microg/ml, as well as 101.534 and 129.957 microg/ml, respectively. When adult schistosomes were exposed to the medium containing chloroquine, lumefantrine or artemether at higher concentrations of 100 or 120 microg/ml for 72 h, no or only individual worms died. Hence the LC50 and LC95 of these 3 drugs could not be determined. In other in vitro test, adult schistosomes exposed to quinine 50 micromol/L (20 microg/ml) in combination with 153.4 micromol/L (100 microg/ml) hemin, all worms died within 72 h post incubation. While the worms exposed to 50 micromol/L (26 microg/ml) chloroquine combined with the same concentration of hemin, only 18.8%(3/16) of worm died at 72 h post exposure. Unexpectedly, in schistosomes exposed to pyronaridine at a toxic concentrations of 50 micromol/L (46 microg/ml) in combination with 153.4 mol/L (100 microg/ml) hemin for 72 h, all of the worms were protected from the toxic action induced by pyronaridine, which revealed in normal motor activity and appearance of morphology in majority of the worms. In in vivo test, mice infected with adult schistosomes were treated orally with chloroquine, pyronaridine or lumefantrine at a daily dose of 400 mg/kg for 3 days, or intraperitoneally with chloroquine or pyronaridine at a daily dose of 100 mg/kg for 2 or 3 days, no apparent efficacy was seen. When mefloquine, quinine, quinidine or artemether were administered orally to infected mice at a single dose of 400 mg/kg or 200 mg/kg (mefloquine), all groups of mice treated showed moderate or higher efficacy with worm burden reductions of 61.1%-98.1%. CONCLUSION: Among the seven antimalarial drugs tested, their inhibitions of hemozoin (beta-hematin) exhibit no definite correlation to their in vitro and in vivo antischistosomal activity. Quinine in combination with hemin shows synergistic effect against schistosomes in vitro. While antagonist effect is observed in pyronaridine combined with hemin.


Subject(s)
Antimalarials/pharmacology , Hemeproteins/metabolism , Schistosoma japonicum/drug effects , Animals , Antimalarials/classification , Mice
13.
Proc Natl Acad Sci U S A ; 109(22): 8511-6, 2012 May 29.
Article in English | MEDLINE | ID: mdl-22586124

ABSTRACT

Human malaria infection begins with a one-time asymptomatic liver stage followed by a cyclic symptomatic blood stage. All high-throughput malaria drug discovery efforts have focused on the cyclic blood stage, which has limited potential for the prophylaxis, transmission blocking, and eradication efforts that will be needed in the future. To address these unmet needs, a high-throughput phenotypic liver-stage Plasmodium parasite screen was developed to systematically identify molecules with liver-stage efficacy. The screen recapitulates liver-stage infection by isolating luciferase-expressing Plasmodium berghei parasites directly from the salivary glands of infected mosquitoes, adding them to confluent human liver cells in 384-well plates, and measuring luciferase activity after a suitable incubation period. Screening 5,375 known bioactive compounds identified 37 liver-stage malaria inhibitors with diverse modes of action, as shown by inhibition time course experiments. Further analysis of the hits in the Food and Drug Administration-approved drug subset revealed compounds that seem to act specifically on the liver stage of infection, suggesting that this phase of the parasite's life cycle presents a promising area for new drug discovery. Notably, many active compounds in this screen have molecular structures and putative targets distinctly different from those of known antimalarial agents.


Subject(s)
Antimalarials/pharmacology , Liver/drug effects , Malaria/prevention & control , Plasmodium berghei/drug effects , Animals , Anopheles/parasitology , Antimalarials/classification , Drug Evaluation, Preclinical , Hep G2 Cells , Humans , Inhibitory Concentration 50 , Insect Vectors/parasitology , Life Cycle Stages , Liver/parasitology , Liver/pathology , Malaria/parasitology , Malaria, Falciparum/parasitology , Malaria, Falciparum/prevention & control , Male , Mice , Mice, Inbred C57BL , Plasmodium berghei/growth & development , Plasmodium berghei/isolation & purification , Plasmodium falciparum/drug effects , Plasmodium falciparum/growth & development , Treatment Outcome
14.
PLoS Med ; 9(2): e1001169, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22363211

ABSTRACT

BACKGROUND: Malaria remains a disease of devastating global impact, killing more than 800,000 people every year-the vast majority being children under the age of 5. While effective therapies are available, if malaria is to be eradicated a broader range of small molecule therapeutics that are able to target the liver and the transmissible sexual stages are required. These new medicines are needed both to meet the challenge of malaria eradication and to circumvent resistance. METHODS AND FINDINGS: Little is known about the wider stage-specific activities of current antimalarials that were primarily designed to alleviate symptoms of malaria in the blood stage. To overcome this critical gap, we developed assays to measure activity of antimalarials against all life stages of malaria parasites, using a diverse set of human and nonhuman parasite species, including male gamete production (exflagellation) in Plasmodium falciparum, ookinete development in P. berghei, oocyst development in P. berghei and P. falciparum, and the liver stage of P. yoelii. We then compared 50 current and experimental antimalarials in these assays. We show that endoperoxides such as OZ439, a stable synthetic molecule currently in clinical phase IIa trials, are strong inhibitors of gametocyte maturation/gamete formation and impact sporogony; lumefantrine impairs development in the vector; and NPC-1161B, a new 8-aminoquinoline, inhibits sporogony. CONCLUSIONS: These data enable objective comparisons of the strengths and weaknesses of each chemical class at targeting each stage of the lifecycle. Noting that the activities of many compounds lie within achievable blood concentrations, these results offer an invaluable guide to decisions regarding which drugs to combine in the next-generation of antimalarial drugs. This study might reveal the potential of life-cycle-wide analyses of drugs for other pathogens with complex life cycles.


Subject(s)
Antimalarials/pharmacology , Malaria/drug therapy , Plasmodium berghei/drug effects , Plasmodium falciparum/drug effects , Plasmodium yoelii/drug effects , Animals , Antimalarials/chemistry , Antimalarials/classification , Culicidae/parasitology , Drug Resistance, Multiple , Humans , Liver/parasitology , Malaria/parasitology , Malaria/transmission , Malaria, Falciparum/drug therapy , Malaria, Falciparum/parasitology , Malaria, Falciparum/transmission , Mice/parasitology , Plasmodium berghei/growth & development , Plasmodium falciparum/growth & development , Plasmodium yoelii/growth & development , Species Specificity
15.
J Travel Med ; 19(6): 357-60, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23379705

ABSTRACT

BACKGROUND: Malaria continues to represent a significant risk for some travelers and malaria chemoprophylaxis has remained an important countermeasure. Trends in antimalarial use may be influenced by a number of factors, including the availability of antimalarials, increasing resistance, the issuing of updated guidelines for malaria chemoprophylaxis, and continuing education. The aim of this study was to investigate the trends in prescription of antimalarial drugs, particularly those recommended for chemoprophylaxis in Australia, from 2005 to 2009. METHODS: In 2011, data were extracted from the online Australian Statistics on Medicines reports published by the Pharmaceutical Benefits Advisory Committee, Drug Utilization Committee, on antimalarials used in Australia for the period 2005 to 2009. RESULTS: Among the drugs solely used as antimalarial drugs from 2005 to 2009, atovaquone plus proguanil and melfloquine were the most commonly prescribed antimalarials. Mefloquine prescriptions increased by 38% from 2005 to 2008 before decreasing by 17% from 2008 to 2009. The number of prescriptions for atovaquone plus proguanil has trebled during the period. Prescriptions for proguanil have dropped over 90% from 2005 to 2009. The diaminopyrimidines, pyrimethamine-containing antimalarials, have mostly been removed from the prescription drug list. Prescriptions for chloroquine have reduced by 66% from 2005 to 2008 and chloroquine was only available on special access from 2009. Artemether plus lumefantrine combination has been used in relatively small quantities and only on special authority from 2007 to 2009. Quinine prescriptions have fallen by 60%. Although a considerable quantity of doxycycline was prescribed, it was unknown how much was intended for malaria chemoprophylaxis. CONCLUSIONS: The prescription of antimalarials in Australia was consistent with the national guidelines with the most commonly prescribed antimalarials being atovaquone plus proguanil, mefloquine, and most likely doxycycline. Other antimalarials previously used for chemoprophylaxis have continued to be removed from the prescriber list between 2005 and 2009. The prescriptions of quinine may be becoming displaced by newer antimalarial drugs for treatment, but this needs further investigation.


Subject(s)
Antimalarials/classification , Drug Prescriptions , Malaria/prevention & control , Practice Patterns, Physicians' , Antimalarials/therapeutic use , Australia/epidemiology , Chemoprevention/methods , Chemoprevention/statistics & numerical data , Chemoprevention/trends , Drug Prescriptions/classification , Drug Prescriptions/statistics & numerical data , Drug Therapy, Combination , Drug Utilization Review , Humans , Malaria/epidemiology , Practice Guidelines as Topic , Practice Patterns, Physicians'/statistics & numerical data , Practice Patterns, Physicians'/trends
16.
Mol Biochem Parasitol ; 181(2): 171-7, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22108433

ABSTRACT

In order to maximise compliance, the future antimalarial treatment should ideally require just a single-dose administration. This, in turn, demands new fast-acting effective drugs. Currently, methods to measure the in vitro killing rate of antimalarials are based on parasite growth. We have developed and validated a method to determine and classify antimalarial agents based on their cidal or static activity following quantitative Real Time PCR (RT-PCR) analysis. The method described here is a fast, reliable and user-friendly technique with a medium throughput. Metabolic activity of the parasite is followed by measuring mRNA expression levels of several genes during 5 parasite life cycles. mRNA from the parasite culture is then retrotranscribed to cDNA and quantified by RT-PCR. This new method provides a rapid and reproducible way to accurately measure the antimalarial activity of new compounds in vitro against Plasmodium falciparum.


Subject(s)
Antimalarials/pharmacology , Drug Evaluation, Preclinical/methods , Plasmodium falciparum/drug effects , RNA, Messenger/analysis , Antimalarials/classification , Gametogenesis/drug effects , Gene Expression Regulation/drug effects , Genes, Protozoan/genetics , Plasmodium falciparum/genetics , RNA, Messenger/metabolism
17.
Internist (Berl) ; 52(12): 1407-13, 2011 Dec.
Article in German | MEDLINE | ID: mdl-22071912

ABSTRACT

Plasmodium falciparum and to some extent malaria caused by other species of Plasmodia can quickly lead to cerebral malaria, acute renal failure, or acute respiratory distress syndrome. The mortality rate for patients with severe malaria lies around 10%. Malaria must be given priority in the differential diagnosis of travelers returning febrile from endemic areas. Treatment requires prompt administration of safe and fast-acting antimalarials, which in severe malaria is treatment with quinine or artesunate. Hospitals must be prepared to diagnose and treat malaria patients-or have a standard operating procedure for transferring the patient to a specialized center.


Subject(s)
Antimalarials/classification , Antimalarials/therapeutic use , Malaria/diagnosis , Malaria/drug therapy , Humans
18.
Mem Inst Oswaldo Cruz ; 106 Suppl 1: 142-58, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21881769

ABSTRACT

The isolation of bioactive compounds from medicinal plants, based on traditional use or ethnomedical data, is a highly promising potential approach for identifying new and effective antimalarial drug candidates. The purpose of this review was to create a compilation of the phytochemical studies on medicinal plants used to treat malaria in traditional medicine from the Community of Portuguese-Speaking Countries (CPSC): Angola, Brazil, Cape Verde, Guinea-Bissau, Mozambique and São Tomé and Príncipe. In addition, this review aimed to show that there are several medicinal plants popularly used in these countries for which few scientific studies are available. The primary approach compared the antimalarial activity of native species used in each country with its extracts, fractions and isolated substances. In this context, data shown here could be a tool to help researchers from these regions establish a scientific and technical network on the subject for the CPSC where malaria is a public health problem.


Subject(s)
Antimalarials/therapeutic use , Malaria/drug therapy , Medicine, Traditional , Phytotherapy/methods , Plants, Medicinal/classification , Angola , Antimalarials/classification , Antimalarials/isolation & purification , Atlantic Islands , Brazil , Cabo Verde , Guinea-Bissau , Humans , Language , Mozambique
19.
Food Chem Toxicol ; 49(6): 1335-9, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21419820

ABSTRACT

Artesunate is a derivate of artemisinin that is both an antimalarial agent and acts cytotoxically on tumor cells. Despite its therapeutic use, its in vivo genotoxic potential has still not been evaluated. This study, therefore, was an investigation into the effects of a single oral administration of artesunate with an in vivo comet assay that analyzed leukocytes from peripheral blood and liver cells, and a micronucleus (MN) assay of bone marrow cells from male Swiss mice. The artesunate was administered by oral gavage at doses of 5, 50 and 100 mg/kg. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio). The results demonstrate that artesunate induced significant DNA damage only in liver cells and that high doses of artesunate caused an increase in the mean number of micronucleated polychromatic erythrocytes (MNPCE). Under our experimental conditions, artesunate showed weak genotoxic effects at low doses and clastogenic effects at high doses. The PCE/NCE ratio indicated no cytotoxicity. The data obtained suggest caution about either continuous or high-dose use of artesunate by humans.


Subject(s)
Antimalarials/toxicity , Artemisinins/toxicity , Bone Marrow Cells/drug effects , Comet Assay/methods , Micronucleus Tests/methods , Mutagens/toxicity , Animals , Antimalarials/classification , Artemisinins/classification , Artesunate , Bone Marrow Cells/pathology , Cell Survival/drug effects , DNA Damage , Doxorubicin/toxicity , Erythrocytes/drug effects , Erythrocytes/pathology , Hepatocytes/drug effects , Hepatocytes/pathology , Leukocytes, Mononuclear/drug effects , Male , Mice , Micronuclei, Chromosome-Defective/chemically induced , Mutagens/classification
20.
South Sudan med. j ; 4(2): 30-32, 2011. tab
Article in English | AIM (Africa) | ID: biblio-1272165

ABSTRACT

In the February 2011 issue of SSMJ we covered the pathophysiology; and clinical and laboratory diagnosis of malaria (1; 2; 3). In this article we deal with the treatment of uncomplicated malaria. Management of malaria among pregnant women and children; and treatment of severe malana will be published in future issues of this journal


Subject(s)
Antimalarials/classification , Drug Therapy , Health Education , Malaria, Falciparum , South Sudan , Treatment Failure
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