Praziquantel

Praziquantel is an anti-parasitic medication used in the treatment of several types of parasitic worms. It works by interfering with the function of the mouth parts of the worm.
Side effects include loss of coordination, abdominal pain, vomiting, headache and allergic reaction. It is contraindicated when a parasite affects the eyes and for women who are breastfeeding, although it can be used during pregnancy.
Dosage and duration depend on the type of worm. For example, a single dose is usually sufficient to treat Schistosomiasis.
Medicine interaction is rare and generally affects the efficacy of the praziquantel rather than posing a danger to the patient. 
Praziquantel at Wikipedia