The anthelmintic action of praziquantel.

Although fairly expensive (around US$4.00 per single dose) praziquantel is now the most favoured drug against all forms of schistosomiasis, and against many other helminth infections. It is now marketed by four companies: E. Merck and Bayer (F.R.G.), Ames-Myers (USA), and Shin-Poon Pharmaceuticals (S. Korea). Administration of praziquantel typically causes paralysis of susceptible worms, or damage to their tegument, making them more vulnerable to host enzymes or antibody-dependent immune effector mechanisms. Other effects may also be involved. Here, Bill Harnett reviews the range of anthelmintic effects displayed by this remarkable drug.