Triclabendazole

Two controlled efficacy studies were conducted to determine the effective dose of fosfatriclaben (FTCB) and compare its fasciolicidal efficacy with that of three commercial products against eggs and adult stages of Fasciola hepatica in artificially infected cattle. In study 1, 20 trematode-free Holstein Friesian steers were infected on day 0 with 500 F. hepatica metacercariae. Ten weeks after infection and the steers were confirmed to be positive for trematode eggs through a modified sedimentation method. On day 75, they were divided into five groups of four animals each for treatment. Group 1 (G1) served as the untreated control; G2, G3, and G4 received FTCB at 4, 6, and 8 mg/kg/intramuscularly (IM), respectively. G5 received a combined treatment of triclabendazole (TCBZ) (12 mg/kg IM + ivermectin (0.2 mg/kg IM). Individual faecal analyses were performed on days -8, 0, 70, 75, and 105 to evaluate the reduction in trematode eggs. Four weeks after treatment, the steers were humanely slaughtered to harvest the livers and remove the parasites present in the bile ducts. Efficacy was evaluated by the reduction in fecal egg counts or in number of adult parasites, compared to the untreated control. The effective FTCB dose was 6 mg/kg. Once the effective dose was determined, study 2 was conducted on another 20 steers infected with 500 F. hepatica metacercariae, to compare the effectiveness of FTCB with three commercials fasciolicides. All procedures were performed as described in study 1, and treatments were as follows: Group 1 (G1), closantel (5 mg/kg subcutaneously (SC)); G2, TCBZ (12 mg/kg IM) + ivermectin (0.2 mg/kg IM); G3, FTCB (6 mg/kg IM); G4, triclabendazole (12 mg/kg) + albendazole (5 mg/kg/PO (orally); and G5 served as an untreated control. The results indicated that all tested compounds were highly effective in the reduction of faecal egg excretion (99.7-100%) and adult parasites (98.9-100%), except closantel, which exhibited low efficacy (74.4%) when tested against adult trematodes. We concluded that the effective dose of FTCB for cattle was 6 mg/kg IM, which is half the recommended clinical dose of the commercial combination of TCBZ and ivermectin. The fasciolicidal efficacy of FTCB was like the other three flukicides in reducing adult F. hepatica and Fasciola eggs; however, closantel was not sufficiently efficient against adult flukes.

Hepatobiliary fascioliasis has two phases, each requiring specific management approaches. Triclabendazole has been widely effective in treating the two phases of clinical fascioliasis and endoscopic retrograde cholangiopancreatography (ERCP) in the biliary phase. We aimed to characterize presentations of hepatobiliary fascioliasis and highlight the role of ERCP in management.

This retrospective cohort includes patients diagnosed with clinical hepatobiliary fascioliasis between January 2013 and December 2022. Demographic data, clinical presentation, laboratory and radiological investigations, treatment, and endoscopy reports were collected from the records of 62 participants. Patients were divided into two groups: acute hepatic and chronic biliary phases.

Thirty-six patients were in the biliary phase, and 26 were in the hepatic phase. All patients were from rural areas, and females were predominant (76%). Hypereosinophilia was detected in 92% of acute cases and 58% of chronic biliary cases. In chronic biliary cases, the levels of liver biochemicals, including alanine transaminase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), and bilirubin, were higher at levels of 189 ± 76, 127 ± 47, 268 ± 77, and 2.4 ± 0.7 respectively, compared to acute hepatic cases, 35.6 ± 8.2, 32.7 ± 4.3, 69.2 ± 45.45, and 0.58 ± 0.01. The corresponding P-values were 0.003, 0.001, <0.001, and <0.001, respectively. Triclabendazole effectively cured 93.5% of patients and was used in combination with ERCP in biliary-phase cases where the fluke was extracted from the biliary system in 34 patients (94.4%). Three patients (8.8%) were diagnosed with post-ERCP pancreatitis. None of the patients experienced bleeding, perforation, or required biliary stenting.

Clinical fascioliasis could manifest in acute hepatic or chronic biliary phases. Hypereosinophilia was more evident in the hepatic phases, while ALT, AST, GGT, and bilirubin were higher in the biliary phase. Triclabendazole is effective in the hepatic phase and when combined with ERCP in the biliary phase. ERCP is highly effective for relieving obstruction and treating biliary fascioliasis.