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)

The sensitivity of Plasmodium falciparum infections to pyrimethamine-sulfadoxine was studied in 18 Indonesian patients in Jayapura, Irian Jaya. In 16 of the 18 patients parasitaemia was cleared by day 6 and the patients remained without parasitaemia through day 28. Two of the 18 patients had late recrudescences consistent with RI-type resistance; one each on days 14 and 21. Pyrimethamine-sulfadoxine is still an effective antimalarial for most patients with falciparum malaria in Jayapura.
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PMID:Pyrimethamine-sulfadoxine still effective against Plasmodium falciparum in Jayapura, Irian Jaya: RI-type resistance in 2 of 18 patients. 330 84

During the period of June to October 1985, a study in vivo was made on 162 patients suffering from malaria by P. falciparum, in order to evaluate the sensitivity of the parasite to the drugs: Chloroquine, Amodiaquine and Pyrimethamine-Sulfadoxine (Fansidar). As an alternative treatment, in the resistant cases, Quinine with Fansidar or Quinine with Tetracycline was given. The following cases of resistance were found: 17 cases to Chloroquine (5-RI, 9-RII, 3-RIII), 7 cases to Amodiaquine (5-RI, 2-RII) and 2 cases to Fansidar (1-RI, 1-RII). It is recommended that the epidemiologic studies of the resistance by P. falciparum to the anti-malarials be increased, following up the evolution of its scope, and the organization of a program to fight against malaria. Also the use of Fansidar is recommended as the principal medicine against P. falciparum in malaria without complications, in the zones where there is strong resistance to the 4-amino-quinoleines. In case of multi-resistance in malaria by P. falciparum, the use of Quinine is recommended. At a prophylactic level we do not advise the use of Chloroquine as the only medicine, nor the use of Fansidar because of its potential toxic effects.
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PMID:[Pharmacoresistance of Plasmodium falciparum in Rwanda: an in vivo study]. 331 Nov 92

The widespread emergence of chloroquine-resistant Plasmodium falciparum led to the formulation of an effective, fixed combination of two antimalarial agents, pyrimethamine and the long-acting sulfonamide sulfadoxine, for prophylaxis and treatment. These drugs act at sequential steps to inhibit the formation of tetrahydrofolate in the parasite. Recently, their use for malaria prophylaxis has been associated with severe, at times fatal, cutaneous reactions including erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. These reactions have necessitated a major reassessment of the indications for pyrimethamine-sulfadoxine use and increased the search for pharmacologic, immunologic and behavioral approaches to the prophylaxis and treatment of infection with P. falciparum. Pyrimethamine-sulfadoxine may be effective in preventing recurrent pneumonia caused by Pneumocystis carinii in patients with the acquired immunodeficiency syndrome, but life-threatening cutaneous reactions have also been reported in this setting.
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PMID:Use of pyrimethamine-sulfadoxine (Fansidar) in prophylaxis against chloroquine-resistant Plasmodium falciparum and Pneumocystis carinii. 355 13

The dapsone-pyrimethamine combination (100 mg of dapsone, 12.5 mg of pyrimethamine [Folaprim; Maloprim, one tablet a week) is considered to provide adequate prophylaxis for Plasmodium falciparum malaria, but to be inadequate for the prevention of P. vivax malaria. Field trials and case reports, however, have shown the comparable efficacy of this combination in the suppression of parasitaemias caused by both parasites. In Lae, Papua New Guinea, 12 patients with clinical signs of malaria had serum concentrations of dapsone-pyrimethamine which were consistent with appropriate weekly use of this combination. The fact that 10 of these patients had P. vivax malaria supports the hitherto unsubstantiated view that dapsone-pyrimethamine can be ineffective in suppressing parasitaemias caused by this parasite. In the two patients with P. falciparum malaria, host factors rather than parasite resistance to dapsone-pyrimethamine were implicated in the development of the parasitaemias.
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PMID:Inadequate prophylaxis of malaria with dapsone-pyrimethamine. 388 12

A prospective study of imported chloroquine-resistant falciparum malaria in the Netherlands is described. From 1979 to 1983, 77 non-immune patients were investigated; in 41 (53%) decreased sensitivity of Plasmodium falciparum to chloroquine could be confirmed. Signs and symptoms in these patients differ from the classical picture. Resistance to sulfadoxine-pyrimethamine (Fansidar) was established in 6 patients. Parasitaemia was found twice during dapsone-pyrimethamine (Maloprim) prophylaxis. The implications for advice on treatment and prophylaxis are discussed.
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PMID:Chloroquine-resistant falciparum malaria imported into the Netherlands. 388 83

For the past 300 years antimalarial dosage regimens have not been based on pharmacokinetic information. However, now that this information is available, it is appropriate to examine current recommendations for prophylaxis and treatment. In healthy subjects, the cinchona alkaloids (quinine and quinidine), primaquine and proguanil (chloroguanide) are all rapidly eliminated with half-lives (t1/2 beta) of between 6 and 12 hours. Hepatic biotransformation accounts for approximately 80, 96 and 50% of their total clearance, respectively. In malaria, the pharmacokinetic properties of quinine and quinidine are significantly altered with a decrease in the apparent volume of distribution (Vd), prolongation of the elimination half-life, and a reduction in systemic clearance (CL) that is proportional to the severity of infection. Red cell concentrations and plasma protein binding are both increased in severe disease. Parenteral quinine or quinidine should be given by slow intravenous infusion rather than by intravenous or intramuscular injection, and a loading dose is necessary in severe infections. Chloroquine (t1/2 beta 6 to 50 days) and mefloquine (t1/2 beta 6.5 to 33 days) have extensive tissue distribution and prolonged activity after a single dose. Both drugs are concentrated in erythrocytes and 55% of chloroquine and 98% of mefloquine in plasma is bound to protein. The pharmacokinetics of chloroquine are complex and, because of the extremely long beta phase, difficult to accurately define. Pyrimethamine (t1/2 35 to 175 hours) has more limited tissue distribution, plasma and erythrocyte concentrations are similar, and 85% of the drug in plasma is bound to plasma proteins. The clearance of quinine, mefloquine and pyrimethamine appears to be higher in children than in adults. Currently, most of the information available on disposition of antimalarial drugs in humans is derived from studies in healthy adult subjects. More information is required on their pharmacokinetics in malaria, pregnancy, and in young children.
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PMID:Clinical pharmacokinetics of antimalarial drugs. 389 40

A reversed-phase high performance liquid chromatography method was developed to simultaneously estimate serum concentrations of dapsone (DDS), monoacetyldapsone (MADDS), and pyrimethamine (PYR) in 34 young adult Chinese men after they had taken the sixth weekly dose of Maloprim for malaria prophylaxis. Serum concentrations of DDS, MADDS, and PYR after 24 h were (mean +/- SEM) 374 +/- 31.3, 310 +/- 30.4, and 121 +/- 7.9 ng/ml, respectively. The 72-h serum concentrations of DDS, MADDS, and PYR were (mean +/- SEM) 134 +/- 21.6, 115 +/- 17.9, and 80 +/- 7.2 ng/ml, respectively. Serum concentrations of DDS and MADDS in many subjects after 120 h were less than 20 ng/ml, while mean +/- SEM concentration of PYR was 53 +/- 5.6 ng/ml. Acetylator phenotyping of the subjects showed that there were 31 (91%) fast acetylators, three (9%) intermediate acetylators, and no slow acetylators.
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PMID:Simultaneous estimation of serum concentrations of dapsone, monoacetyldapsone, and pyrimethamine in Chinese men on maloprim for malaria prophylaxis using reversed-phase high performance liquid chromatography. 390 34

A five-year malaria chemoprophylaxis study has begun with Maloprim in children aged three months to five years and pregnant women in a population of 13,000 in the area of Farafenni, The Gambia. Sensitivity of Plasmodium falciparum to pyrimethamine, Maloprim and chloroquine was assessed in vivo and in vitro in rural Gambian villages before drug intervention. 569 children aged one to seven years inclusive were sampled at the end of the wet season of 1982; 46% had positive blood films. All afebrile children were treated with a single dose of one of the antimalarials under study. Febrile children were treated with chloroquine. 109 infected children were retested 7 to 10 days after treatment and none showed asexual parasitaemia. 83 micro in vitro tests were successfully performed from fingerprick blood samples and the results confirmed the in vivo study. Pyrimethamine in combination with dapsone, in the proportion present in Maloprim, i.e., 1:8, showed a synergistic effect, the mean effective dose of pyrimethamine being reduced 13 times at the 50% inhibitory level.
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PMID:Susceptibility of Plasmodium falciparum in The Gambia to pyrimethamine, Maloprim and chloroquine. 390 54

The efficacy of chloroquine and pyrimethamine as malaria chemoprophylactics was investigated in young Nigerian children. Chloroquine resistance had not been documented in the study area; pyrimethamine resistance was probably present but uncommon. Children who received weekly chemoprophylaxis with pyrimethamine had a lower prevalence of malaria parasitaemia and malaria antibodies than children who received weekly chemoprophylaxis with chloroquine. Pyrimethamine given monthly gave a comparable degree of protection to chloroquine given weekly. Chloroquine frequently induced vomiting in young children and this may have impaired its efficacy as a prophylactic. We conclude that, in an area where neither chloroquine nor pyrimethamine resistance is prevalent, pyrimethamine is a better chemoprophylactic for young children than chloroquine.
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PMID:A comparison of chloroquine and pyrimethamine as malaria chemoprophylactics in young Nigerian children. 409 53

The malaria infection rates in non-immune residents of Dar es Salaam on various chemoprophylactic regimens were compared with that (37.1%) in those not taking prophylactic antimalarials. Among 647 people resident in Dar es Salaam for 1-6 years the two groups with the lowest infection rates by person-episodes (2.0% and 1.5%) were those taking proguanil 200 mg daily alone or with chloroquine base 300 mg weekly. Infection rates (16.9% and 14.0%) were also significantly lower than in the no-prophylaxis group in those taking chloroquine base 300 mg weekly combined with 'Fansidar', 'Maloprim' (each one tablet weekly), or proguanil 100 mg daily. No significant reduction in the malaria attack rate was found in those taking chloroquine base 300 mg or 600 mg weekly (31.2%), pyrimethamine 25 mg weekly (27.3%), proguanil 100 mg daily (46.4%), maloprim one tablet weekly (40.4%), or a combination of chloroquine base 300 mg weekly and pyrimethamine 25 mg weekly (27.1%). Similar results were obtained when the infection rates per year of exposure were compared. Proguanil was associated with fewest user complaints and fansidar with most.
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PMID:Chemoprophylaxis of malaria in non-immune residents in Dar es Salaam, Tanzania. 614 92


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