S H Xiao1, J Q You, J Y Mei, P Y Jiao, H F Guo, Z Feng. 1. Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine, WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, China. tmrc@fudan.ac.cn
Abstract
AIM: To study the effect of artemether (Art) for prevention of schistosomal infection. METHODS: Rabbits with single infection or reinfection with Schistosoma japonicum cercariae were treated intramuscularly (i.m.) or intragastrically (i.g.) with Art 5 -20 mg.kg-1 on d 7-15 after the first infection, followed by various regimens. RESULTS: When rabbits were injected i.m. Art 7.5 mg.kg-1 (i.e., one half of the effective dose given i.g. on d 7) followed by once every week for twice, the female worm reduction rate was only 42%. In infected rabbits treated i.g. with Art 10-20 mg.kg-1 given in the same administration schedule, the female worm reduction rates were > 91%. When Art 15 mg.kg-1 was given to rabbits on d 7-14 and the following dose of the drug was given at intervals of 7-14 d, the female worm reduction rates were > 94%. In rabbits reinfected with cercariae, the female reduction rate of Art given i.g. once a week for 3 times since d 8 after the first infection was 96% which was similar to that given once a week twice since d 14 after the first infection. CONCLUSION: Art should be given i.g. on d 7-15 after infection, followed by repeated dosing once every 7-15 d for a total of 3 doses. Art given i.g. daily for 2 consecutive days or given at 1-wk intervals since 7-15 d after infection also showed preventive effect.
AIM: To study the effect of artemether (Art) for prevention of schistosomal infection. METHODS:Rabbits with single infection or reinfection with Schistosoma japonicum cercariae were treated intramuscularly (i.m.) or intragastrically (i.g.) with Art 5 -20 mg.kg-1 on d 7-15 after the first infection, followed by various regimens. RESULTS: When rabbits were injected i.m. Art 7.5 mg.kg-1 (i.e., one half of the effective dose given i.g. on d 7) followed by once every week for twice, the female worm reduction rate was only 42%. In infected rabbits treated i.g. with Art 10-20 mg.kg-1 given in the same administration schedule, the female worm reduction rates were > 91%. When Art 15 mg.kg-1 was given to rabbits on d 7-14 and the following dose of the drug was given at intervals of 7-14 d, the female worm reduction rates were > 94%. In rabbits reinfected with cercariae, the female reduction rate of Art given i.g. once a week for 3 times since d 8 after the first infection was 96% which was similar to that given once a week twice since d 14 after the first infection. CONCLUSION:Art should be given i.g. on d 7-15 after infection, followed by repeated dosing once every 7-15 d for a total of 3 doses. Art given i.g. daily for 2 consecutive days or given at 1-wk intervals since 7-15 d after infection also showed preventive effect.