In the US, Praziquantel (praziquantel systemic) is a member of the drug class anthelmintics and is used to treat Beef Tapeworm Infection (Taenia saginata) , Cysticercus cellulosae , Dog Tapeworm Infection , Dwarf Tapeworm Infection (Hymenolepis nana) , Echinococcus , Fasciolopsis buski - Intestinal Fluke , Fish Tapeworm Infection , Heterophyes heterophyes - Intestinal Fluke , Liver Fluke , Metagonimus yokogawai - Intestinal Fluke , Naophyetus salmincola , Opisthorchis viverrini - Liver Fluke , Paragonimus westermani - Lung Fluke , Pork Tapeworm Infection (Taenia solium) , Schistosoma haematobium , Schistosoma japonicum , Schistosoma mansoni and Schistosoma mekongi .
Praziquantel is well absorbed (about 80%) from the gastrointestinal tract . However, due to extensive first-pass metabolism , only a relatively small amount enters systemic circulation. Praziquantel has a serum half-life of to hours in adults with normal renal and liver function. Metabolites have a half-life of 4 to 5 hours. In patients with significantly impaired liver function ( Child-Pugh score B and C), the serum half-life is increased to 3 to 8 hours. Praziquantel and its metabolites are mainly excreted renally; within 24 h after a single oral dose, 70 to 80% is found in urine, but less than % as the unchanged drug. Praziquantel is metabolized through the cytochrome P450 pathway via CYP3A4 . Agents that induce or inhibit CYP3A4 such as phenytoin , rifampin , and azole antifungals will affect the metabolism of praziquantel.