Vivax malaria: preliminary observations following a shorter course of treatment with artesunate plus primaquine.

The standard adult treatment regimen for Plasmodium vivax malaria is chloroquine (1500 mg over 3 d) plus primaquine (15 or 30 mg daily for 14 d), but patient compliance tends to be poor with the lengthy course. Preliminary observations are reported on the efficacy of a shorter treatment course - artesunate (200mg twice a day for 2 d) plus primaquine (22.5mg base twice a day for 7 d) - given to 28 adult patients infected with P. vivax in Viet Nam. All patients responded quickly to treatment with mean (SD) parasite and fever clearance times of 14.2 (4.0) and 18.6 (8.4) h, respectively. The high dose of primaquine was generally well tolerated, and only one patient (3.6%) had a recurrence of parasitaemia during 28 d of follow-up. As most patients infected with Southeast Asian strains of P. vivax have their first relapse within 28 d after treatment with rapidly eliminated blood schizonticides, the absence of parasitaemia in the remaining 27 patients suggests that this drug regimen was active against both blood and liver stages. Further studies are needed to confirm that this rapidly acting, short artesunate-primaquine regimen can result in better patient compliance and treatment outcomes than the chloroquine-primaquine regimen.

Fatty food does not alter blood mefloquine concentrations in the treatment of falciparum malaria.

Food has been reported to increase the bioavailability of mefloquine in healthy volunteers, but its role in increasing blood mefloquine concentrations in malaria patients treated with mefloquine is unclear. In this study, we compared blood mefloquine concentrations after the administration of artesunate (8 mg/kg) and mefloquine (15 mg/kg) over 12h with either a low-fat (approximately 3g of fat) or high-fat (approximately 30 g of fat) meal for the treatment of Plasmodium falciparum malaria in 12 Vietnamese patients. No statistical differences were detected in the following kinetic parameters between the low-fat (n=6) and high-fat (n=6) groups, respectively: maximum blood mefloquine concentrations (2838+/-531 ng/ml and 2556+/-657 ng/ml, 95% CI -486 to 1050 ng/ml, P=0.43) and the area under the blood mefloquine concentration versus time curves (246.8+/-58.3 microg.h/ml and 238.3+/-28.4 microg.h/ml, 95% CI -50.5 to 67.5 microg.h/ml, P=0.75). A fatty meal does not appear to increase the bioavailability of mefloquine in malaria patients and should not affect the response of malaria infections to treatment.