naphthoquinones and fanasil--pyrimethamine-drug-combination

The use of anti-malarial drug combinations with artemisinin or with one of its derivatives is now widely recommended to overcome drug resistance in falciparum as well as vivax malaria. The fixed oral dose artemisinin-naphthoquine combination (ANQ, ARCO) is a newer artemisinin-based combination (ACT) therapy undergoing clinical assessment. A study was undertaken to assess the safety, efficacy and tolerability of ANQ combination in areas of multi-drug resistance to generate preliminary baseline data in adult population of Papua New Guinea.. The clinical assessment was an open-labeled, two-arm, randomized study comparing ANQ combination as a single dose regimen and three days regimen (10 mg/kg/day) of chloroquine plus single dose sulphadoxine-pyrimethamine (CQ+SP) for the treatment of uncomplicated falciparum malaria with 28 days follow-up in an adult population. The primary outcome measures for efficacy were day 1, 2, 3 7, 14 and 28-day cure rates. Secondary outcomes included parasite clearance time, fever clearance time, and gametocyte carriage. The main outcome measures for safety were incidences of post-treatment clinical and laboratory adverse events.. Between June 2005 and July 2006, 130 patients with confirmed uncomplicated P. falciparum were randomly assigned to receive ANQ and CQ+SP, only 100 patients (51 in ANQ group and 49 in CQ+SP group) were evaluated for clinical and parasitological outcomes. All the patients treated with ANQ and CQ+SP showed adequate clinical and parasitological response with 28 days follow-up. The cure rate for ANQ on day 1, 2, 3, 7, 14, and 28 was 47%, 86%, 92%, 94%, 94% and 94%, respectively. Recrudescence account for 6%; all were cleared on day 21. For CQ+SP treated group the cure rates were 24%, 67%, 82%, 82%, 84% and 88%, respectively. Recrudescence accounted for 10%; all were cleared on day 28 except for one patient. Both regimens were well tolerated with no serious adverse events. The proportion of gametocyte carriers was higher in CQ+SP treated group than ANQ treatment (41% versus 12%; p < 0.05).. While these data are not themselves sufficient, it strongly suggests that the ANQ combination as a single dose administration is safe and effective for the treatment of uncomplicated P. falciparum malaria in the adult population of Papua New Guinea and deserves further clinical evaluation.

Topics: Adolescent; Adult; Animals; Antimalarials; Artemisinins; Blood; Chloroquine; Drug Combinations; Humans; Malaria, Falciparum; Male; Middle Aged; Naphthoquinones; Papua New Guinea; Parasitemia; Plasmodium falciparum; Pyrimethamine; Sulfadoxine; Treatment Outcome; Young Adult

Whether administration of folic acid to children with malaria anemia is helpful is controversial. Therefore, we conducted a randomised, placebo-controlled trial of 14 days of treatment with folic acid (1 mg/d) in Zambian children with malaria anemia treated with either sulfadoxine/pyrimethamine (SP) or atovaquone/proguanil (AP). Among children who received SP, the prevalence of parasitemia was higher in children treated with folic acid than among those given placebo at days 3, 7, and 14 after the start of treatment, and the difference at day 3 was statistically significant (P = 0.013). Folic acid treatment had no effect on parasitemia in children treated with AP. Administration of folic acid led to a small increase in packed cell volume over that seen in the placebo group at days 14 and 28 after the start of treatment.

Topics: Anemia; Animals; Antimalarials; Atovaquone; Child; Child, Preschool; Drug Combinations; Folic Acid; Hematinics; Humans; Infant; Malaria, Falciparum; Naphthoquinones; Parasitemia; Population Density; Proguanil; Pyrimethamine; Sulfadoxine; Treatment Failure; Zambia

The efficacy and safety of a fixed-dose combination of atovaquone and proguanil hydrochloride (Malarone) were compared with chloroquine or pyrimethamine/sulfadoxine in patients with acute falciparum malaria in northern Peru. Patients were initially randomized to receive 1,000 mg atovaquone and 400 mg proguanil hydrochloride daily for 3 days (n=15) or 1,500 mg chloroquine (base) over a 3 day period (n=14) (phase 1). The cure rate with chloroquine was lower than expected and patients were subsequently randomized to receive a single dose of 75 mg pyrimethamine and 1,500 mg sulfadoxine (n=9) or atovaquone/proguanil as before (n=5) (phase 2). In phase 1, atovaquone/proguanil was significantly more effective than chloroquine (cure rate 100% [14/14] vs. 8% [1/13], P<0.0001). In phase 2, atovaquone/proguanil and pyrimethamine/sulfadoxine were both highly effective (cure rates 100% [5/5] and 100% [7/7]). There were no significant differences between treatment groups in parasite or fever clearance times. Adverse events were typical of malarial symptoms and did not differ significantly between groups. Overall efficacy of atovaquone/proguanil was 100% for treatment of acute falciparum malaria in a region with a high prevalence of chloroquine resistance.

Topics: Adolescent; Adult; Aged; Animals; Antimalarials; Atovaquone; Chloroquine; Drug Combinations; Drug Resistance, Microbial; Drug Therapy, Combination; Female; Humans; Malaria, Falciparum; Male; Microbial Sensitivity Tests; Middle Aged; Naphthoquinones; Peru; Proguanil; Pyrimethamine; Sulfadoxine; Treatment Outcome

Atovaquone-proguanil has recently been introduced for the treatment and prophylaxis of malaria. However, resistance of Plasmodium falciparum is increasingly reported. We assessed P. falciparum polymorphisms associated with resistance to atovaquone (cytochrome b, cytb) and to cycloguanil, the active compound of proguanil (dihydrofolate reductase, dhfr) in 100 isolates from northern Ghana. None of these exhibited cytb codon 268 mutations. Moreover, no dhfr V16A, S108T or I164L mutations linked with cycloguanil resistance were detected. However, dhfr triple mutants (S108N-I51L-C59R) conferring resistance to proguanil and sulphadoxine-pyrimethamine were seen in 51% of the isolates. In northern Ghana, P. falciparum cytb codon 268 mutations associated with atovaquone resistance are absent. Although proguanil appears to act synergistically with atovaquone in a way different from its antifolate property, the abundance of dhfr polymorphisms will likely compromise the prevention of dissemination of atovaquone-resistant parasites once emerged.

Topics: Animals; Antimalarials; Atovaquone; Child, Preschool; Cytochromes b; Drug Combinations; Drug Resistance; Drug Synergism; Drug Therapy, Combination; Female; Folic Acid Antagonists; Ghana; Humans; Infant; Malaria, Falciparum; Male; Mutation; Naphthoquinones; Plasmodium falciparum; Polymorphism, Restriction Fragment Length; Proguanil; Pyrimethamine; Sulfadoxine; Tetrahydrofolate Dehydrogenase; Triazines

Malaria continues to be a problem for children returning or immigrating to industrialized countries from tropical regions. Proper diagnosis begins with clinical suspicion. In nonimmune children, malaria typically presents with high fever that might be accompanied by chills and headache. Symptoms and signs may be more subtle in partially immune children, and anemia and hepatosplenomegaly may also be present. Children may present with respiratory distress and/or rapidly progressing cerebral malaria that manifests as altered sensorium and, sometimes, seizures. Thick blood smears help to determine when infection is present, but a single smear without parasites is not sufficient to rule out malaria. Thin blood smears aid in identifying the species of parasite. Treatment must include careful supportive care, and intensive care measures should be available for treating children with complicated Plasmodium falciparum malaria. Medical regimens can include mefloquine, atovaquone-proguanil, sulfadoxine-pyrimethamine, quinine or quinidine, clindamycin, doxycycline, chloroquine, and primaquine.

Topics: Animals; Antimalarials; Atovaquone; Child; Chloroquine; Drug Combinations; Humans; Malaria; Malaria, Falciparum; Mefloquine; Naphthoquinones; Plasmodium falciparum; Proguanil; Pyrimethamine; Sulfadoxine

Blackwater fever is a clinical entity characterized by acute intravascular hemolysis classically occuring after the re-introduction of quinine in long-term residents in Plasmodium falciparum endemic areas and repeatedly using the product.. The symptomatology appears brutally with emission of porto-colored urine, icterus, pallor, nausea, fever and acute renal failure. The hemolytic-like anemia is immediately severe. Parasitemia is mild or absent. The mechanism of renal failure is tubular necrosis.. Well known at the start of the 20th century, blackwater fever has become exceptional since 1950, when quinine was replaced by chloroquine. The disease reappeared in 1990, following the re-utilization of quinine because of resistance to chloroquine. Thereafter, several cases have been described with halofantrine and mefloquine, two new molecules similar to quinine (amino-alcohol family). The physiopathogenesis of the disease is not well known, however it would appear that the concomitance of a double sensitivization of the red blood cells to the P. falciparum red blood cells and to the amino-alcohols is necessary to provoke the hemolysis.. The severity of the clinical picture often requires initial management in intensive care unit. Nowadays, however, prognosis is good and the disease usually regresses without after effects.

Topics: Adolescent; Adult; Aged; Antimalarials; Atovaquone; Blackwater Fever; Critical Care; Diagnosis, Differential; Drug Combinations; Humans; Mefloquine; Middle Aged; Naphthoquinones; Phenanthrenes; Prognosis; Proguanil; Pyrimethamine; Quinine; Sulfadoxine