Efficacy of ivermectin on the infectivity of Leishmania major promastigotes.

Ivermectin is widely used as an antiparasitic drug for livestock and recently used for some human parasites. The effect of ivermectin on the infectivity of Leishmania major promastigotes was studied in Syrian golden hamsters. The results showed that hamsters infected with promastigotes treated for one day with 100 micrograms/ml ivermectin in culture medium did not develop skin lesion at the site of infection. However, amastigotes were demonstrated in Giemsa stained splenic smears. On the other hand, promastigotes treated for two days with 90 micrograms/ml ivermectin did not acquired the infection. i.e. the promastigotes died or lost their infectivity.