Antiparasitic agents
Class Summary
Praziquantel and triclabendazole are the 2 agents that the World Health Organization (WHO) recommended to treat paragonimiasis. Praziquantel is the most commonly used and has a cure rate of 80-90%.[1, 10]
Triclabendazole is currently not approved for use in the United States but is available on a compassionate care protocol from the Centers for Disease Control and Prevention Drug Services at (404) 639-3670. In areas where triclabendazole is available, it is becoming first-line therapy for treatment of paragonimiasis. Triclabendazole is administered at a dose of 10 mg/kg/d for 3 days or 20 mg/kg/d divided in 2 doses for 1 day. Cure rates have been as high as 98.5%.[1]
A study done in Ecuador randomized 62 patients with confirmed pulmonary paragonimiasis to one of four groups (praziquantel or one of three groups with differing doses of triclabendazole).[11] This study found improved clinical response and quicker decreases in sputum production in patients treated with triclabendazole. Parasitological response was found to be more rapid in those individuals treated with triclabendazole. The study suggested that triclabendazole may have more rapid killing of adult flukes but the mechanism of action remains unknown.[11]
Older therapies (eg, bithionol [30-50 mg/kg qod for 10-15 doses] or niclofolan), despite their effectiveness (cure rates ≥ 90%), have unacceptable adverse effect profiles compared with praziquantel.
Praziquantel (Biltricide)
Increases cell membrane permeability in susceptible worms, resulting in loss of intracellular calcium, massive contractions, and paralysis of musculature. Produces vacuolization and disintegration of schistosome tegument, followed by attachment of phagocytes to parasite and death.
Tab should be swallowed whole with some liquid during meals. Keeping tab in mouth may reveal bitter taste, which can produce nausea or vomiting.
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