Triclabendazole is an anthelmintic medication used to treat infections caused by parasitic worms. The World Health Organization (WHO) includes triclabendazole on its List of Essential Medicines, underscoring its importance in public health. It has been available as a generic drug since the late 1990s, increasing its accessibility.
Medical Uses
Triclabendazole primarily treats fascioliasis (liver fluke disease) and paragonimiasis (lung fluke disease). Fascioliasis is caused by liver flukes, such as Fasciola hepatica and Fasciola gigantica, which can infect humans after consuming contaminated raw water plants like watercress or food. These parasites typically reside in the liver and bile ducts. Paragonimiasis results from lung fluke infections, posing a public health concern in endemic areas.
Triclabendazole is considered the preferred medication for treating fascioliasis and shows promise as an alternative treatment for paragonimiasis. It demonstrates effectiveness against all stages of the liver fluke, including immature, juvenile, and adult worms. Clinical studies have shown high efficacy in treating both acute and chronic forms of fascioliasis.
How Triclabendazole Works
Triclabendazole disrupts the internal structure and metabolic processes of parasitic flukes. After ingestion, the drug is absorbed and converted in the liver into active metabolites, primarily sulfoxide and sulfone. These metabolites are taken up by the parasite’s outer body covering, the tegument.
The active metabolites interfere with the formation and function of microtubules within the fluke’s cells. Microtubules act as an internal scaffolding, supporting cell shape, division, and movement. By inhibiting microtubule polymerization, triclabendazole causes this internal structure to break down, leading to impaired cellular functions. This disruption also affects the parasite’s energy production within its mitochondria, leading to energy depletion and hindering its viability.
Administration and Side Effects
Triclabendazole is taken orally in tablet form, typically as one or two doses. It should be taken with food to enhance absorption. If a tablet cannot be swallowed whole or split, it can be crushed and mixed with applesauce; this mixture should be consumed within four hours.
Common side effects may include abdominal pain, headache, dizziness, nausea, vomiting, sweating, and decreased appetite. Some symptoms, such as abdominal pain, might be a reaction to dying parasites being expelled rather than a direct drug effect.
Serious, but rare, side effects include:
- Hives
- Rash
- Itching
- Swelling of the face, lips, tongue, or throat
- Difficulty breathing
- An abnormal heartbeat (prolonged QT interval)
If any of these serious symptoms appear, immediate medical attention is necessary.
Veterinary Applications
Triclabendazole is also used in veterinary medicine for managing liver fluke infections in livestock. It has been employed in animals such as sheep and cattle since the 1980s to control Fasciola species. These parasitic infections can lead to health problems and economic losses in the agricultural sector.
Reports of triclabendazole resistance in Fasciola hepatica have emerged in livestock in various regions, including Australia and Europe, which is a concern for animal health management. Despite these challenges, its widespread use helps mitigate the impact of fascioliasis on livestock health and agricultural productivity.