Triclabendazole
Anthelmintics
Anthelmintics
Benzimidazole for the liver fluke Fasciola, active against young and adult flukes; vital in Andean areas where fascioliasis is common.
Quick facts
- Group
- Anthelmintics
- Target
- Fasciola liver fluke (exact molecular target not established)
- Used for
- Fascioliasis · Alternative for paragonimiasis
- Key effects
- Abdominal pain · Headache · Itching
- Monitor
- Abdominal pain · Stool examination for eggs
- ATC
- P02BX04
No doses: the clinician sets them by the current guideline.
Mechanism of action
Triclabendazole is a benzimidazole, but unlike albendazole it is reserved for liver flukes. After absorption it is quickly oxidised to a sulfoxide metabolite, the form that acts on Fasciola. It kills both the immature flukes that migrate through the liver and the adults living in the bile ducts, which is why it works in the acute and the chronic phase. Its precise molecular target is still not settled.
- Absorbed better with food and oxidised to the active sulfoxide
- The sulfoxide reaches flukes in liver tissue and bile ducts
- Kills immature and adult Fasciola
- Flukes in liver and bile ducts are killed in both disease phases
Indications
- Fascioliasis (Fasciola hepatica and F. gigantica), acute and chronic; the drug of choice
- Alternative for paragonimiasis (lung fluke)
Adverse effects
Common
- Abdominal pain, nausea, vomiting, diarrhoea and decreased appetite
- Headache, dizziness and heavy sweating
- Itching, hives and fever
Contraindications
- Allergy to triclabendazole or other benzimidazoles (albendazole, mebendazole)
Key interactions
- Food
- Increases absorption; the dose is taken with a meal.
- Praziquantel
- Not an alternative: praziquantel, which works for most other flukes, is usually inactive against Fasciola.
- QT-prolonging medicines (for example amiodarone, sotalol, citalopram, haloperidol, some fluoroquinolones and macrolides)
- Possible additive QT prolongation; the clinician reviews them and may monitor more closely.
What is monitored
- Abdominal pain, fever, or yellow skin or eyes in the days after treatment
- Stool examination for eggs and blood eosinophils some weeks later, to confirm cure
- Repeat treatment or referral if eggs persist (possible resistance)
Administration and safety
- Oral, with food
- It is not commercially available in every country; in some it comes through health ministries or WHO donation
Pregnancy and breastfeeding
There are no human data on its use in pregnancy, so the risk cannot be estimated; a clinician weighs the benefit.
Nursing care
- Ask about eating raw watercress or other freshwater plants
- Give the doses with food
- Ask about heart rhythm problems or a prolonged QT interval, and report yellow skin or eyes
- Teach prevention: no raw aquatic plants and safe drinking water
Pharmacokinetics
- Absorption
- Oral; food increases absorption, so it is taken with a meal.
- Metabolism
- Rapidly oxidised to the sulfoxide (active) and sulfone; little parent drug reaches the blood.
Test yourself
Think of the answer, then tap the question to see it.
What is the drug of choice for fascioliasis?
Triclabendazole, which is active against both immature and adult Fasciola.
Why is praziquantel not used for Fasciola even though it works for most other flukes?
Fasciola is usually not susceptible to praziquantel; triclabendazole is used instead.
How do people usually become infected with Fasciola hepatica?
By eating raw watercress or other freshwater plants, or drinking water, contaminated with the larvae.
Why is a history of prolonged QT interval asked about before triclabendazole?
Triclabendazole can prolong the QT interval, so heart rhythm problems and other QT-prolonging drugs are reviewed first.
Connections
← Back to the class: Anthelmintics
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Clinical Overview of Fasciola (Centers for Disease Control and Prevention (CDC), 2026); Triclabendazole: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); Foodborne trematode infections (World Health Organization (WHO), 2026); Triclabendazole Treatment Failure for Fasciola hepatica Infection among Preschool and School-Age Children, Cusco, Peru (Emerging Infectious Diseases (CDC), 2021).
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Representative model, for educational purposes only.