Praziquantel is used extensively in veterinary practice. The veterinary versions of praziquantel, however, may be produced by different firms, and may use different production processes. Veterinary products are not subject to the same Good Manufacturing Practices (GMP) regulations that apply to human products. In particular, the quality control standards and the sterility requirements are far less stringent.
Among the veterinary products in the market that we could identify, praziquantel is the active ingredient in Droncit (Bayer), which is used for the control of Echinococcus multilocularis, as a 34 mg tablet, or as an injectable containing 56.8 mg/ml of praziquantel (CFR, 1993b; Jordan et al., 1993). Echinococcus multilocularis is considered one of the most deadly of all zoonotic helminthic infections, and, therefore, is a zoonosis of increasing global concern. Dogs, cats, foxes, and coyotes are the most common hosts. Humans can become infected with the larval stage of this parasite, which leads to alveolar hydatid disease. Use of praziquantel for the treatment of this disease in animals, therefore, has important public health implications.
Droncit is also available in a 11.5 mg oral tablet form for the treatment of cestode-related infestations in cats (CFR, 1993a). Further, praziquantel is a constituent of a combination drug, Drontal (Bayer), which contains 18.2 mg praziquantel and 72.6 mg pyrantel, and is used in animal practice for the removal of tapeworms, hookworms and large roundworms in cats (CFR, 1993c) .
Praziquantel is also marketed by Miles Pharmaceuticals, the US subsidiary of Bayer, as Vercom, an oral paste formulation. A similar febantel-praziquantel oral paste is available for the removal of hookworms and ascarids in dogs (CFR, 1988). Finally, a US company, Mobay Corporation, manufactures an OTC version of praziquantel for use in dogs and cats, which was approved by the FDA effective January 23, 1990 (CRF, 1990).
Recently, a new use for praziquantel was proposed in veterinary practice, with public health implications. Praziquantel was used for the treatment of ducks, which are the carriers of the trematode that causes Swimmer’s Itch in humans (Blankespoor and Reimink, 1991).