Efficacy and safety of artemether against a natural Fasciola hepatica infection in sheep

Triclabendazole is the current drug of choice against Fasciola spp. infections in livestock, but resistance has become a major problem. In this study, we assessed the efficacy and safety of artemether, a derivative of artemisinin, in sheep with a low natural Fasciola hepatica infection. Artemether was administered orally or intramuscularly; sheep were monitored for 8 h posttreatment and then once daily for adverse events, and drug efficacy was estimated by fecal egg count reductions and worm burden reductions. Single 40- and 80-mg/kg oral doses of artemether showed no effect on F. hepatica egg and worm burden. Treatment with a single 160-mg/kg intramuscular dose of artemether significantly reduced the egg burden (64.9%) and worm burden (91.3%). At half this dose, a worm burden reduction of 65.3% was obtained, which was still statistically significant (P