Efficacy of single-dose 500 mg mebendazole in soil-transmitted helminth infections: a review

Soil-transmitted helminthiasis (STH) is caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), and Ancylostoma duodenale and Necator americanus (hookworms). Mebendazole is one of the recommended preventive chemotherapy agents for STH. This review summarizes the efficacy data from 29 studies with single-dose 500 mg mebendazole in STH treatment and compares the results with those of a recently conducted phase 3 study of a 500 mg mebendazole chewable tablet against A. lumbricoides and T. trichiura infections. Studies that reported efficacy results against at least one STH infection were selected from the literature and efficacy data by each STH type were abstracted and pooled. Single-dose 500 mg mebendazole treatment resulted in a cure rate of 92.6% (range: 72.5-100%) for A. lumbricoides, 27.6% (range: 8.4-100%) for T. trichiura and 25.5% (range: 2.9-91.1%) for hookworms. Egg reduction rate for A. lumbricoides was 97.9% (range: 89.8-100%), for T. trichiura it was 72.9% (range: 31.6-93.0%) and for hookworms it was 72.0% (range: -6.5% (denoting an increase in egg count) to 98.3%). Similar results were observed in the studies that were placebo-controlled. In the phase 3 study, the cure rate and egg reduction rate reported was 83.7% and 97.9%, respectively, for A. lumbricoides and 33.9% and 59.7%, respectively, for T. trichiura. In conclusion, single-dose 500 mg mebendazole showed a high cure rate against A. lumbricoides and a substantial reduction in faecal egg count for all STH types. These results are consistent with the recently conducted phase 3 study of a new 500 mg chewable mebendazole tablet.