Prophylactic activity of praziquantel in animals infected with Schistosoma japonicum

Praziquantel 400 mg/kg given ig to mice 2-4 h before infection, reduced the worm rate by about 90%, when given 2 h after infection, reduced the worm number by 47-84%.The number of 3-21 d old worm surviving treatment was not significantly reduced. In rabbits,a dose of 60 or 100 mg/kg was given 4 h before and after infection, the worm reduction rate was 20-38%. When praziquantel polyethylene glycol solution 50 mg/kg was given to the dogs im 4 h before and after infection, the worm reduction rates were 61 and 44%,respectively. However, a significant effect of praziquantel was again exerted on 35 d old schistosomes in both rabbits and dogs, resulting in reduction rates of 86-97% and 100%, respectively.