Effect of a broad spectrum antiparasitic drug "ivermectin" in acute and chronic experimental giardiasis using different dose regimens.

In this study, the maximal excretion of Giardia lamblia cysts was three weeks post infection (p.i). Administration of ivermectin subcutaneously proved to be effective in treating hamsters infected for 2 and 3 weeks respectively. It was found that the dose of 300 microg/kg b.w. was much more efficient than 200 mg/kg b.w. The cure rate was 99.1% in the former, and 98.7% in the later. The difference was statistically significant. In chronic giardiasis where infection was kept for 6 weeks, the cure rate was 99.5% two weeks after treatment with 300 g/kg b.w. of ivermectin. Assessment of cure was performed also by histopathological examination of upper 2/3 of small intestine of the hamsters. Localization and counting of the parasite were carried out immunohistochemically. The mean number of trophozoites decreased markedly after treatment with the large dose either acute or chronic giardiasis.