Which antiparasitic drugs are effective against Eurytrema spp. in animals, and are any approved for human use?
Executive summary
Praziquantel, supported by in vitro work and multiple veterinary references, emerges as the principal antiparasitic recommended against Eurytrema spp. in livestock, with albendazole and nitroxinil reported as alternative or adjunctive options in animals; triclabendazole has shown little or no efficacy against Eurytrema in studies [1] [2] [3] [4]. The literature supplied does not document any drug explicitly approved for treatment of human eurytremiasis, and few clinical treatment protocols have been validated in vivo, leaving human-use questions unresolved in the available reporting [3] [4].
1. The veterinary evidence: praziquantel is the lead candidate
Multiple veterinary and parasitology sources identify praziquantel as effective against adult Eurytrema pancreaticum and as the drug of choice in many experimental and field reports, including in vitro trials that produced 100% parasite death and veterinary dosing recommendations for ruminants [2] [3] [4]. The Merck Veterinary Manual specifically cites praziquantel regimens (20 mg/kg for 2 days) as having been reported effective in production animals, underlining that praziquantel is the primary anthelmintic relied upon in practice and in the literature for pancreatic fluke control [1].
2. Other veterinary drugs and mixed results: albendazole, nitroxinil, triclabendazole
Albendazole has been reported as effective at standard livestock doses (7.5 mg/kg in sheep, 10 mg/kg in cattle) in veterinary guidance, and nitroxinil has been used in multi-dose regimens that reduced fecal egg output in field work, suggesting these agents may play roles where praziquantel use is limited or as part of integrated control attempts [1] [3]. By contrast, published in vitro comparisons show triclabendazole failing to kill Eurytrema in tests where praziquantel succeeded, and authors explicitly note triclabendazole did not present efficacy in those trials [3] [4].
3. The scientific caveat: few validated protocols and limited in vivo data
Researchers and reviews warn that formal, repeatable chemotherapy protocols for eurytremiasis are scarce—there are only a handful of in vivo trials and no universally accepted treatment algorithm—so reports of “efficacy” often rest on small trials, egg-count reductions, or laboratory exposures rather than broad, controlled field data [3]. This uncertainty has practical consequences: while praziquantel and albendazole are cited as effective, their success may depend on dosing, delivery form, host species, and local parasite strains, and outcomes in Brazil and other endemic areas remain variable [2] [3].
4. Human infections and regulatory gaps in the provided reporting
The supplied sources acknowledge occasional human infection with Eurytrema spp. but do not provide controlled clinical treatment studies or regulatory approvals for any drug specifically for human eurytremiasis; reviewers explicitly state that treatment of infection is not yet accomplished in some endemic countries and that human cases may be underreported [3] [5]. Because none of the provided documents lists an approved human regimen or regulatory authorization for treating human Eurytrema infection, the literature at hand cannot support claims that a drug is approved for human eurytremiasis [3] [4].
5. Policy, practice and potential hidden agendas in veterinary sources
Commercial and technical veterinary outlets emphasize praziquantel’s broad anthelmintic profile and provide dosing tables, which can be useful but also reflect a market for broad-spectrum anthelmintics and may understate evidence gaps for specific parasites like Eurytrema; independent reviews and academic papers call for more species-level molecular work and controlled trials before declaring definitive protocols [2] [3]. Readers should therefore weigh manufacturer- or practitioner-focused guidance against academic critiques noting few in vivo trials and an absence of validated human treatment pathways [2] [3].
6. Bottom line and limits of the current reporting
For animals, praziquantel is the best-supported antiparasitic against Eurytrema spp., with albendazole and nitroxinil reported as alternatives and triclabendazole showing poor efficacy in trials; however, robust, standardized treatment protocols are lacking and efficacy can depend on dose and formulation [2] [1] [3] [4]. Regarding human use, the sources do not document any drug specifically approved for treating human eurytremiasis, and the available literature stops short of clinical recommendations for humans—this absence of evidence in the supplied reporting is itself the most important limitation [3] [4].