Triclabendazole

Triclabendazole treatment produces percentage decreases of the fluke egg output by 15.3%, 4.3% and 36.6%, respectively, in sheep, dairy cows and heifers, these results indicate the presence of TCBZ-resistant Fasciola hepatica in sheep and cattle on this farm. ^[1] Triclabendazole sulphoxide (50 mg/mL) results in extensive damage to the tegument of triclabendazole-susceptible F. hepatica, whereas triclabendazole-resistant flukes shows only localized and relatively minor disruption of the tegument covering the spines. ^[2]

Triclabendazole is metabolized into a number of compounds, depending on the route of administration, plasma levels peak at 18-24 hours (Triclabendazole sulphoxide) and 36-48 hours (Triclabendazole sulphone), neither Triclabendazole nor any other metabolites can be detected in plasma. Triclabendazole sulphoxide blocks the transport of secretory bodies from the cell body to the tegumental surface, the block occurs at the site of their formation by the Golgi complex in the cell body, in their movement through the cytoplasmic connections to the syncytium, and in their movement from the base to the apex of the syncytium. Triclabendazole binds to the colchicine binding site on the β-tubulin molecule and this has been used at the basis for evaluating the relative acitvity of Triclabendazole. ^[3] Triclabendazole is administered intraruminally at 10 mg/kg to sheep, Triclabendazole (TCBZ) metabolites present in plasma are only TCBZ sulphoxide (TCBZ-SO) and TCBZ sulphone, their maximum concentrations (greater than 13 mg/mL) at 18 hours and 36 hours, respectively. Triclabendazole metabolites are specifically bound to plasma albumin, which is believed to exert a major influence on the duration of plasma TCBZ metabolite concentrations and consequent exposure of liver fluke. ^[4] Triclabendazole (40 mg/kg) kills 99% of adult flukes in the rat. ^[5]