FALCIPARUM-MALARIA IN EASTERN THAILAND - A RANDOMIZED TRIAL OF THE EFFICACY OF A SINGLE-DOSE OF MEFLOQUINE

Reported are the results of a randomized trial of a single dose of mef loquine (15 mg/kg or 25 mg/kg body weight) for the treatment of uncomp licated multidrug-resistant falciparum malaria. Of the 110 adult patie nts enrolled in the study 57 were randomly assigned to the 15 mg/kg gr oup and 53 to the 25 mg/kg group. The baseline characteristics of the patients did not differ significantly in the two groups, except that t hose in the 15 mg/kg group had lower haemoglobin levels. Adverse effec ts following treatment were commoner in the 25 mg/kg group, hut not si gnificantly so. Seven patients (6%) did not complete the 42-day follow -up. The parasitological failure rates in the 15 and 25 mg/kg groups w ere, respectively, 50% (28/56) and 43% (23/53) on day 28, and 62% (33/ 53) and 56% (28/50) on day 42. Treatment failures were not correlated with the serum mefloquine concentrations on day 2, and 13 out of 19 pa tients with serum mefloquine concentrations >2000 mu g/l on day 2 show ed an R response during the follow-up. The mean ratio between the conc entrations of the (SR)-(-) and (RS)-(+) enantiomers of mefloquine on d ay 2 was 3.37, indicating that there are differences in their pharmaco kinetics. Re-treatment of patients who showed an R response with seven days of quinine (30 mg.kg(-1).day(-1))+ tetracycline (25 mg.kg(-1).da y(-1)) was successful in 93% of the cases.