FASINEX 10 %

Indications

• Fascioliasis
• Infection caused by _Fasciola hepatica_
• Infection caused by _Fasciola gigantica_

Dosage

Children: Refer to the BNF for Children for appropriate dosing in paediatric patients.

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Triclabendazole acts on _Fasciola_ species through an unclear mechanism, though it is believed to involve absorption by the outer body covering of the worms. This results in a reduction of the resting membrane potential, inhibition of tubulin function, and disruption of protein and enzyme synthesis necessary for the survival of the parasites. These effects culminate in decreased motility, disruption of the worm's outer surface, and inhibition of spermatogenesis and embryonic cell development. Resistance may develop through alterations in drug uptake and metabolism.

Pharmacodynamics

Triclabendazole and its active metabolites, sulfoxide and sulfone, are effective against both immature and mature stages of _Fasciola hepatica_ and _Fasciola gigantica_. Caution is advised as the drug may prolong the QT interval, necessitating ECG monitoring in patients with a history of QT prolongation or those on other QT-prolonging medications.

Pharmacokinetics

Triclabendazole is absorbed after oral administration and is metabolized in the liver to its active metabolites. The pharmacokinetics profile reveals that these metabolites are responsible for its anthelmintic activity. The exact elimination half-life and excretion details are not provided, but changes in drug metabolism can affect the drug's efficacy and safety.

Adverse effects

• Nausea
• Vomiting
• Abdominal pain
• Headache
• Rash
• Dizziness
• QT interval prolongation

Precautions

• Monitor ECG in patients with a history of QT prolongation or who are taking medications known to prolong the QT interval.
• Use with caution in patients with hepatic impairment.

Pregnancy

Triclabendazole should only be used in pregnancy if the benefits justify the potential risks to the fetus. Animal studies have shown adverse effects.

Breast-feeding

It is not known whether triclabendazole is excreted in human milk. Caution is advised when administering to breastfeeding women.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Oral tablet
• Suspension

Mechanism of action

Triclabendazole is an anthelmintic agent against _Fasciola_ species. The mechanism of action against Fasciola species is not fully understood at this time. In vitro studies and animal studies suggest that triclabendazole and its active metabolites (_sulfoxide_ and _sulfone_) are absorbed by the outer body covering of the immature and mature worms, causing a reduction in the resting membrane potential, the inhibition of tubulin function as well as protein and enzyme synthesis necessary for survival. These metabolic disturbances lead to an inhibition of motility, disruption of the worm outer surface, in addition to the inhibition of spermatogenesis and egg/embryonic cells. **A note on resistance** In vitro studies, in vivo studies, as well as case reports suggest a possibility for the development of resistance to triclabendazole. The mechanism of resistance may be multifactorial and include changes in drug uptake/efflux mechanisms, target molecules, and changes in drug metabolism. The clinical significance of triclabendazole resistance in humans is not yet elucidated.

Pharmacodynamics

Triclabendazole and its metabolites are active against both the immature and mature worms of _Fasciola hepatica_ and _Fasciola gigantica_ helminths. **Effect on QT interval** This drug may prolong the cardiac QT interval. Monitor ECG in patients with a history of QT prolongation or who are taking medications known to prolong the QT interval.