Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Artesunate (ART) is a semi-synthetic derivative of artemisinin, the active principle of the Chinese herb Artemisia annua. ART reveals remarkable activity against otherwise multidrug-resistant Plasmodium falciparum and P. vivax malaria. ART has now been analyzed for its anti-cancer activity against 55 cell lines of the Developmental Therapeutics Program of the National Cancer Institute, USA. ART was most active against leukemia and colon cancer cell lines (mean GI50 values: 1.11+/-0.56 microM and 2.13+/-0.74 microM , respectively). Non-small cell lung cancer cell lines showed the highest mean GI50 value (25.62+/-14.95 microM) indicating the lowest sensitivity towards ART in this test panel. Intermediate GI50 values were obtained for melanomas, breast, ovarian, prostate, CNS, and renal cancer cell lines. Importantly, a comparison of ART's cytotoxicity with those of other standard cytostatic drugs showed that ART was active in molar ranges comparable to those of established anti-tumor drugs. Furthermore, we tested CEM leukemia sub-lines resistant to either doxorubicin, vincristine, methotrexate, or hydroxyurea which do not belong to the N.C.I. screening panel. None of these drug-resistant cell lines showed cross resistance to ART. To gain insight into the molecular mechanisms of ART's cytotoxicity, we used a panel of isogenic Saccaromyces cerevisiae strains with defined genetic mutations in DNA repair, DNA checkpoint and cell proliferation genes. A yeast strain with a defective mitosis regulating BUB3 gene showed increased ART sensitivity and another strain with a defective proliferation-regulating CLN2 gene showed increased ART resistance over the wild-type strain, wt644. None of the other DNA repair or DNA check-point deficient isogenic strains were different from the wild-type. These results and the known low toxicity of ART are clues that ART may be a promising novel candidate for cancer chemotherapy.
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PMID:The anti-malarial artesunate is also active against cancer. 1125 Nov 72

Combination therapy that includes artemisinin derivatives cures most falciparum malaria infections. Lowering transmission by reducing gametocyte infectivity would be an additional benefit. To examine the effect of such therapy on transmission, Gambian children with Plasmodium falciparum malaria were treated with standard regimens of chloroquine or pyrimethamine-sulfadoxine alone or in combination with 1 or 3 doses of artesunate. The infectivity to mosquitoes of gametocytes in peripheral blood was determined 4 or 7 days after treatment. Infection of mosquitoes was observed in all treatment groups and was positively associated with gametocyte density. The probability of transmission was lowest in those who received pyrimethamine-sulfadoxine and 3 doses of artesunate, and it was 8-fold higher in the group that received pyrimethamine-sulfadoxine alone. Artesunate reduced posttreatment infectivity dramatically but did not abolish it completely. The study raises questions about any policy to use pyrimethamine-sulfadoxine alone as the first-line treatment for malaria.
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PMID:Artesunate reduces but does not prevent posttreatment transmission of Plasmodium falciparum to Anopheles gambiae. 1126 8

Artesunate is a key antimalarial drug in the treatment of multidrug-resistant Plasmodium falciparum malaria in southeast Asia. We investigated the distribution of counterfeit artesunate tablets by use of the validated, simple, and inexpensive Fast Red TR dye technique. We also aimed to identify distinguishing characteristics of the fake drugs. Of 104 shop-bought "artesunate" samples from Cambodia, Laos, Myanmar (Burma), Thailand, and Vietnam, 38% did not contain artesunate. Characteristics such as cost and physical appearance of the tablets and packaging reliably predicted authenticity. The illicit trade in counterfeit antimalarials is a great threat to the lives of patients with malaria. The dye test will assist national malaria control authorities in urgently needed campaigns to stop this murderous trade.
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PMID:Fake artesunate in southeast Asia. 1170 36

Malaria during pregnancy is associated with an increased risk of severe anaemia and low-birthweight babies. Effective intermittent therapy with pyrimethamine-sulfadoxine (PSD) decreases parasitaemia and severe anaemia and improves birthweight in areas where Plasmodium falciparum is sensitive to this drug. Increasing resistance to PSD is a concern and alternative antimalarial regimens during pregnancy are needed. Artesunate with PSD is a promising antimalarial combination but few data are available on the safety of artemisinins when taken during pregnancy. Outcome of pregnancy was evaluated for 287 women in The Gambia who were exposed in June 1999 to a single dose of the combination artesunate and PSD during a mass drug administration and 172 women who were not exposed. Women who received placebo (40) and those who did not participate in the mass drug administration (132) comprised the non-exposed group. There was no difference in the proportion of abortions, stillbirths, or infant deaths among those exposed or not exposed to the drugs. The mean weight of 18 infants born to mothers who had received artesunate and PSD during the third trimester was 3.10 kg compared to a mean weight of 2.62 kg of the 10 infants of untreated mothers (adjusted P value = 0.05). We found no evidence of a teratogenic or otherwise harmful effect of gestational exposure to artesunate and PSD. Treatment of a self-selected group of pregnant women with PSD and artesunate during pregnancy was associated with a greater birthweight, which may have resulted from clearance of malaria parasites. However, the influence of confounding factors cannot be excluded.
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PMID:The safety of the combination artesunate and pyrimethamine-sulfadoxine given during pregnancy. 1247 94

The case was a 47-year-old Nigerian male who was thought to have contracted malaria in Nigeria and then manifested fever with chill, arthralgia and diarrhea in Japan. The blood test at International Medical Center of Japan revealed thrombocytopenia and anemia. Ring forms of 0.03% of his RBCs and ICT Malaria P.f/P.v test was also positive for Plasmodium falciparum. We prescribed mefloquine to him, but the number of the paresites in his peripheral blood did not decrease, and, in fact, they came to increase (maximum 6.66%) 20 hours after the drug treatment. As clinical condition of malaria were liable to change seriously, intravenous Artesunate (a qinghaosu derivative) was decided to be given additionally to the patient. Consequently the parasites disappeared in 20 hours from his blood but a low grade fever still continued possibly because of cholecystitis. At the same time of Artesunate treatment, hemoglobinuria started and anemia worsened partly because of his G-6-PD deficiency. All pending problems were improved by the time he left Japan and those parasites were finally found to be susceptible for mefloquine by the in vitro susceptibility test. This is the first reported case of falciparum malaria successfully treated with intravenous Artesunate in Japan.
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PMID:[A case of falciparum malaria successfully treated with intravenous artesunate]. 1160 94

The emergence and spread of multidrug-resistant Plasmodium falciparum compromises the treatment of malaria, especially during pregnancy, where the choice of antimalarials is already limited. Artesunate (n=528) or artemether (n=11) was used to treat 539 episodes of acute P. falciparum malaria in 461 pregnant women, including 44 first-trimester episodes. Most patients (310 [57.5%]) received re-treatments after earlier treatment with quinine or mefloquine. By use of survival analysis, the cumulative artemisinin failure rate for primary infections was 6.6% (95% confidence interval, 1.0-12.3), compared with the re-treatment failure rate of 21.7% (95% confidence interval, 15.4-28.0; P=.004). The artemisinins were well tolerated with no evidence of adverse effects. Birth outcomes did not differ significantly to community rates for abortion, stillbirth, congenital abnormality, and mean gestation at delivery. These results are reassuring, but further information about the safety of these valuable antimalarials in pregnancy is needed.
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PMID:Artemisinin antimalarials in pregnancy: a prospective treatment study of 539 episodes of multidrug-resistant Plasmodium falciparum. 1171 93

The single-dose pharmacokinetics of 100 mg of orally administered artesunate (AS) were studied in 6 patient volunteers with uncomplicated falciparum malaria and in 6 healthy volunteers. Plasma concentrations of both the parent drug, AS, and its major metabolite, dihydroartemisinin (DHA), were measured simultaneously by high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). The antimalarial activity of each plasma sample measured by an in vitro bioassay (BA) was used to derive activity concentrations. Artesunate was absorbed rapidly and then almost completely hydrolyzed to DHA in patients, whereas hydrolysis was incomplete in healthy volunteers. The mean +/- standard deviation (SD) maximum concentration (Cmax) of AS was 296+/-110 nmol/L, the time to peak blood level (tmax was 0.71+/-0.66 hr, the half-life (t1/2,z) was 0.41+/-0.34 hr, and the bioavailability over 12 hr (area under the curve [AUC](0-12)) was 253+/-185 nmol hr/L. Measured by HPLC, the Cmax and AUC(0-12) values of DHA in patients with malaria were significantly greater than in volunteers (1,948+/-772 and 1,192+/-315 nmol/L; 4,024+/-1,585 and 1,763+/-607 nmol hr/L, respectively; P < or = 0.05). These differences were even greater when measured by BA. The Cmax for patients with malaria was 2,894+/-2,497 and 795+/-455 nmol/L for volunteers, and AUC(0-12) was 5,970+/-3,625 and 1,307+/-391 nmol hr/L, respectively (P < or = 0.05). In contrast, DHA parameter estimates for t1/2,z and tmax were similar between patients and healthy volunteers, with values of 0.80+/-0.30 versus 0.87+/-0.06 hr and 1.50+/-0.55 versus 1.13+/-0.52 hr, respectively (P > 0.5). Both drug metabolism and tissue protein binding could contribute to the differences between the antimalarial activity of artemisinin drugs in healthy volunteers and malaria infected patients.
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PMID:Comparative pharmacokinetics and effect kinetics of orally administered artesunate in healthy volunteers and patients with uncomplicated falciparum malaria. 1179 63

To compare the effectiveness and safety of quinine sulfate and artesunate with mefloquine for treating second trimester pregnancy in women who suffered from Plasmodium falciparum malaria. The prospective study was done in Srisangwal Hospital, Mae Hong Son, Thailand. Sixty, second to third trimester pregnant patients with P. falciparum infection, were recruited at random. They received either quinine sulfate 10 mg/kg/day for at least 7 days, 29 women (group I), or oral artesunate 2 mg/kg as the first dose, 1 mg/kg every 12 hours orally for at least 5 days together with split doses of mefloquine, 15 mg/kg and 6 hours later 10 mg/kg orally 1 day after artesunate was stopped, 28 women (group II). Three cases (5%) were lost to follow-up before delivery, one case in group I and two cases in group II. After treatment, the mean hematocrit of group I was significantly less than group II (p = 0.000). The PCT (parasite clearance time) and FCT (fever clearance time) of group II were significantly shorter than group I (p = 0.000). None of the patients in both groups had recrudescences within 28 days. Group I had more adverse effects than group II. No adverse neurological effects in pregnancy were found in both groups. The calcification of placenta and IUGR (Intrauterine growth retard) were not different between the two groups (p = 0.964, 0.363 respectively). The PCT was not different between the calcified placenta group and normal placenta group (p = 0.058), but the TTPP (Total time of parasite presentation) was (p = 0.000). TTPP related to low birth weight and low apgar score at 1 minute might be the cause (p = 0.000, 0.000 F = 5.261, 21.627 respectively). TTPP and PCT related to neonatal blood pH and caused low neonatal blood pH (p = 0.000, 0.001 F = 24.351, 11.162 respectively). The physical and neurological development of the babies at 2, 4, 6 and 12 months follow-up, were normal and there were no congenital abnormalities in either group. TTPP relating to fetal outcome, the longer the TTPP, the worse the fetal outcome, so we should diagnose early and treat P. falciparum malaria in pregnancy to prevent fetal jeopardy. Artesunate with mefloquine could shorten the PCT more than quinine sulfate in pregnancy, so the fetal outcome was better than that of quinine sulfate. In cases of prolonged infection before treatment, artesunate might be the alternative treatment of P. falciparum malaria in pregnancy. However, its safety should be carefully studied further with a larger sample size.
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PMID:Randomized trial of artesunate and mefloquine in comparison with quinine sulfate to treat P. falciparum malaria pregnant women. 1180 Mar 3

In areas where multidrug-resistant Plasmodium falciparum (MDR-Pf) is prevalent, only quinine is known to be safe and effective in pregnant women. On the western border of Thailand, 7 days of supervised quinine (30 mg/kg daily) cures two-thirds of P. falciparum-infected women in the 2nd and 3rd trimesters of pregnancy. Artesunate is effective against MDR-Pf and the limited data on its use in pregnancy suggest it is safe. An open randomized comparison of supervised quinine (10 mg salt/kg every 8 h) in combination with clindamycin (5 mg/kg every 8 h) for 7 days (QC7) versus artesunate 2 mg/kg per day for 7 days (A7) was conducted in 1997-2000 in 129 Karen women with acute uncomplicated falciparum malaria in the 2nd or 3rd trimesters of pregnancy. There was no difference in the day-42 cure rates between the QC7 (n = 65) and A7 (n = 64) regimens with an efficacy of 100% in both, confirmed by parasite genotyping. The A7 regimen was also associated with less gametocyte carriage; the average person-gametocyte-weeks for A7 was 3 (95% CI 0-19) and for QC7 was 39 (95% CI 21-66) per 1000 person-weeks, respectively (P < 0.01). There was no difference in gastrointestinal symptoms between the groups but there was significantly more tinnitus in the QC7 group compared to the A7 group (44.9% vs 8.9%; RR 5.1; 95% CI 1.9-13.5; P < 0.001). The favourable results with quinine-clindamycin mean that there is a useful back-up treatment for women with falciparum malaria who experience quinine and artesunate failures in pregnancy. Adherence to the 7-day regimen and cost (US$18.50 per treatment) are likely to be the main obstacles to this regimen.
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PMID:Randomized comparison of quinine-clindamycin versus artesunate in the treatment of falciparum malaria in pregnancy. 1181 39

Artesunate (ARS) is a water-soluble artemisinin derivative that is a potential alternative to quinine for the treatment of severe childhood malaria. We studied the pharmacokinetics and bioavailability of ARS given by the intramuscular (i.m.) route in an open crossover study design. Fourteen children were randomized to receive intravenous (i.v.) ARS in a loading dose (2.4 mg/kg of body weight) followed 12 h later by an i.m. dose (1.2 mg/kg) (group I), and 14 children were randomized to receive i.m. ARS (2.4 mg/kg) followed by an i.v. dose of ARS (1.2 mg/kg) (group II). We carried out a two-compartment analysis of ARS and dihydroartemisinin (DHA; the principal antimalarial metabolite) levels in 21 children (groups I and II combined). Absorption of i.m. ARS was rapid, with the maximum concentration of DHA in serum being achieved in less than 1 h in most children (median time to the maximum concentration of drug in serum, 35.1 min; range, 10.8 to 71.9 min). The absolute bioavailability of DHA was a median of 86.4% (range, 11.4 to 462.1%), the median steady-state volume of distribution was 1.3 liters/kg (range, 0.5 to 7.9 liters/kg), and the median clearance was 0.028 liters/kg/min (range, 0.001 to 1.58 liters/kg/min). There were no major adverse events attributable to ARS. Parasite clearance kinetics were comparable between the two treatment groups. These results support the use of i.m. ARS in children with severe malaria.
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PMID:Intramuscular bioavailability and clinical efficacy of artesunate in gabonese children with severe malaria. 1243 98


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