Abstract

Poor efficacy of antimalarial biguanide-dapsone combinations in the treatment of acute, uncomplicated, falciparum malaria in Thailand

Wilairatana P, Kyle DE, Looareesuwan S, Chinwongprom K, Amradee S, White NJ, Watkins WM
Ann Trop Med Parasitol. 1997;91

Permenent descriptor

Combinations of dapsone with proguanil or chlorproguanil have proved effective in the treatment of chloroquine-resistant falciparum malaria in Africa and for prophylaxis in Asia. These combinations have not been used for treatment in areas with multi-drug-resistant parasites such as in Thailand. Combinations of dapsone (approximately 4 mg/kg) plus ether proguanil (approximately 8 mg/kg; DP regimen; N = 10) or chlorproguanil (approximately 1.4 mg/kg; DC regimen; N = 16) were given once a day for 3 days to adult Thai patients with acute, uncomplicated, falciparum malaria. The two regimens were well tolerated and had no side-effects, but the cure rates, assessed at 28-day follow-up, were only 10% for DP (60% with RI response and 30% with RII) and 14% for DC (29% with RI response and 57% with RII). The mean (S.D.) fever-clearance times in those patients who were cured (S) or whose infections recrudesced (RI response) were 103 (56) h for those given DP and 90 (42) h for 6 those given DC. The corresponding parasite-clearance times were 83 (46) for DP and 53 (21) h for DC. In-vitro susceptibility testing of isolates obtained both before treatment and at recrudescence demonstrated marked resistance to cycloguanil, dapsone, chloroquine and mefloquine. The results demonstrate that short-course treatment with dapsone plus either proguanil or chlorproguanil is ineffective for the treatment of falciparum malaria in Thailand.