RESUMEN
The present study was undertaken to evaluate the anthelmintic effects of fenbendazole against intestinal nematode; Ascaris lumbricoides, hookworm and Trichuris trichiura, and to compare the efficacy in fenbendazole, oxantel-pyrantel pamoate and placebo by means of double blind method. Out of 114 subjects harbouring Ascaris lumbricoides, hookworm and Trichuris trichiura, 36 cases were treated with single dose of fenbendazole, 38 cases with oxantel-pyrantel pamoate, and the remaining 40 cases had received the placebo. The results were as follows: In the group treated with fenbendazole (30-50 mg/kg), the cure rates were 83.9 percent in 31 subjects with Ascaris lumbricoides and 83.3 percent in 18 subjects with hookworm, and only 28.6 percent in 28 subjects with T. trichiura respectively. In the group treated with a single dose of oxantel-pyrantel pamoate (10 mg/mg), the cure rates were 96.7 percent in 30 subjects with A. lumbricoides, 95.2 percent in 21 subjects with hookworm, and 54.6 percent in 33 subjects with T. trichiura. Egg reduction rate was 85.7 percent in T. trichiura cases. On the other hand, the egg negative conversion rates in placebo group were 9.7, 8.3 and 33.3 percent in Ascaris, Trichuris and hookworm infections respectively. The above results showed that fenbendazole was highly effective against Ascaris and hookworm. However, incomparisom with oxantel-pyrantel pamoate, fenbendazole was less effective in regards of A. lumbricoides, hookworm and T. trichiura infections.