Tolerability and efficacy of single-dose diethyl carbamazine (DEC) or ivermectin in the clearance of Wuchereria bancrofti microfilaraemia in Pondicherry, south India.

In a double blind design the tolerability and efficacy of single-dose DEC (6 mg/kg/body weight) or ivermectin (400 microg/kg/body weight) was studied in 30 asymptomatic W. bancrofti parasite carriers each. Although both drugs were tolerated well, the adverse reaction score (DEC 0.5; ivermectin 1.5) and overall incidence (DEC 65.0%; ivermectin 93.3%) were significantly higher in the ivermectin group. Major adverse reactions were fever, headache and myalgia, all of which peaked on the second day post-therapy. Efficacy was measured in terms of proportion of cases clearing parasitaemia and reduction in mean parasite density compared to pre-therapy levels. Although at the end of one year the ivermectin group showed a significantly higher efficacy (34.8%, 97.0%) compared to DEC (8.3%, 83.8%), at the end of the second year there was no significant difference in efficacy between the drugs (73.7%, 99.5% for ivermectin; 47.8%, 98.9% for DEC). The tolerability and efficacy of the two drugs were not significantly different between gender, age and weight classes of patients.