Treatment of Fasciola hepatica Infection
Triclabendazole is the only effective drug for treating Fasciola hepatica infection, with the standard regimen being two doses of 10 mg/kg administered orally 12 hours apart with food. 1
First-Line Treatment Regimen
Triclabendazole 10 mg/kg orally as two doses given 12 hours apart with food is the recommended standard-of-care regimen for chronic fascioliasis, as endorsed by the CDC and recently approved by the FDA. 1
The two-dose regimen (total 20 mg/kg) achieves superior cure rates (93.9%) compared to single-dose therapy (79.4%), making it the preferred approach. 2
Patients should take triclabendazole with food to optimize absorption and efficacy. 3
Clinical Monitoring and Expected Response
Biliary colic-like abdominal pain occurs in approximately 49% of patients between days 2-7 post-treatment, representing expulsion of dead or damaged parasites through the bile ducts—this is an expected therapeutic response, not a complication. 3
This pain typically responds well to spasmolytic therapy within hours and should be anticipated and managed supportively. 3
Efficacy assessment should include stool microscopy for eggs, Fasciola excretory-secretory antigen (FES) testing in feces, and ultrasonography performed pre-treatment and on days 1-7,15,30, and 60 post-therapy. 3
Management of Treatment Failures
Approximately 8-26% of patients fail initial standard-of-care treatment, requiring additional therapeutic interventions. 3, 2
For patients who continue excreting eggs after the initial two-dose regimen, multiple additional courses of triclabendazole can achieve a cumulative cure rate of 74%—the term "triclabendazole resistance" should be used cautiously as many patients ultimately respond to repeated dosing. 4
A practical approach for treatment failures: administer another single dose of triclabendazole 10 mg/kg at day 60 if eggs persist, with continued monitoring until three consecutive stool examinations are negative. 3, 4
Safety Profile
Triclabendazole is generally well-tolerated with minimal side effects beyond the expected biliary colic. 3, 5, 2
Most adverse events (72%) are mild, with only rare severe reactions requiring intervention. 3
One case of transient biochemical cholestasis has been reported (resolving within 2 months), warranting monitoring of liver enzymes on days 1,3,7,15, and 60 post-treatment. 2
Critical Clinical Pearls
No other anthelmintic agents (praziquantel, mebendazole, albendazole) are effective against Fasciola hepatica—triclabendazole is the only option. 1, 5
For acute fascioliasis, evidence is limited as eggs may not yet be present in stool during the prepatent period, making diagnosis and treatment monitoring more challenging. 1
The infection presents with abdominal pain and nausea in the acute phase, progressing to biliary obstruction and hepatic abscess in chronic untreated cases. 6
Eosinophilia is commonly present and can help support the diagnosis alongside imaging and serology. 6