Efficacy of single-dose mebendazole, polymorphic forms A and C, in the treatment of hookworm and Trichuris infections.

A therapeutic trial of single mebendazole, 300 mg polymorph A, 300 mg polymorph C and 500 mg polymorph C, in the treatment of hookworm and Trichuris infections was carried out at primary schools in Southern Thailand. The total of 958 children were randomly allocated in seven treatment groups including the placebo control and the standard dose control (100 mg polymorph C bid for 3 days). The egg reduction rates and the cure rates of 300 mg and 500 mg polymorph C were similar, but inferior to those of the standard dose in both hookworm and Trichuris infections. The efficacy of single dose 300 mg polymorph A was not different from that of the placebo control (alpha = 0.05) in both infections.