Effect of erythromycin on albendazole teratogenicity in pregnant rat

Albendazole is utilized as an anthelmentic agent. One its side effect is teratogenicity. This effect apparently is related to its metabolites especially albendazole sulfoxid. The aim of present study was evaluation effect of erythromycin (as enzyme inhibitor in biotransformation) on albendazole biotransformation and consequently fetal malformation.

Four groups of female pregnant wistar rats (8 rats each group) were used. One group received normal saline (as control group). A single oral dose 30 mg/kg of albendazole was administered to rats on day 10 of gestation in group2. Rats in group3 received albendazole similar group2 and erythromycin at dose 60mg/kg. Rats in group4 received only erythromycin on day 10 of gestation. The rats were euthanatized on day 20 of gestation. The fetuses were harvested and their weight and length and also the weight of placenta were measured. The skeletal malformation of fetus was studied by stereomicroscope after staining by Alizarin red - Alcian blue.

The length and weight of fetuses were significantly decreased by albendazole but erythromycin did not prevent this effect. In group that received only erythromycin, the length and weight of fetuses was similar to control group. Erythromycin decreased albendazole effect on weight of placenta. There was an increase in resorption by erythromycin when co-administrated with albendazole. The incidence of skeletal malformations (mostly of the limbs, vertebrae and palate) decreased significantly by erythromycin when co-administrated with albendazole.

Thus, erythromycin may inhibit albendazole biotransformation and decrease teratogenicity of it metabolites; but this subject needs more detailed evaluation.