In vivo study of the response of Plasmodium falciparum to standard mefloquine/sulfadoxine/pyrimethamine (MSP) treatment among gem miners returning from Cambodia.

An in vivo study of the response of P. falciparum to the combination drug, MSP, was conducted among gem miners who contracted malaria from Cambodia in 1991-1992. High level resistance (RII, RIII responses) was observed in 22.5% of the 40 cases attending Mae Sot malaria clinic, west Thailand border, and in 28.1% of the 96 cases attending Bo Rai malaria clinic, east Thailand border. The observations on in vitro studies conducted prior to the MSP treatment and after recrudescence, together with the findings on adequate mefloquine blood levels strongly indicated the serious deterioration of mefloquine efficacy. The first line treatment for the malaria control program needs to be revised and the use of qinghaosu derivatives considered. Intensive measures to combat spreading of the highly resistant strains to other parts of the country should be taken into account.

Phase III double-blind comparative study of Fansimef and Lariam for the curative treatment of Plasmodium falciparum infections in Thailand.

A double-blind comparative study of Fanismef-mefloquine/sulfadoxine/pyrimethamine (MSP) and Lariam-mefloquine (MEF) for the treatment of falciparum malaria, was carried out at malaria clinics in Kanchanaburi, in western Thailand, in the years 1987 and 1988. The cure rates obtained were 96% for the MSP group and 93% for the MEF and there was no significant difference. Vomiting and diarrhea were common side effects in both the MSP and MEF groups. Less common side effects were epigastric pain, minor skin rashes and dizziness. Significant differences in vomiting and epigastric pain only occurred in the patients who did not have these symptoms before treatment: vomiting MSP 23%, MEF 8%, epigastric pain MSP 22% and MEF 11%.