Praziquantel is an anthelmintic or anti-worm medication. It prevents newly hatched insect larvae (worms) from growing or multiplying in your body. Praziquantel is used to treat infections caused by Schistosoma worms, which enter the body through skin that has come into contact with contaminated water. Praziquantel is also used to treat infection with liver flukes, caused by a type of worm found in East Asia. This worm enters the body while eating contaminated fish. Praziquantel should not be used to treat parasitic infections in the eye.