Journal of Helminthology

Research Papers

Praziquantel adversely affects protoscoleces of Echinococcus granulosus in vitro

R. C. A. Thompsona1, J. A. Reynoldsona1 and Cicelia R. Riddlera1

a1 Division of Veterinary Biology and WHO Collaborating Centre for Echinococcosis/Hydatidosis, School of Veterinary Studies, Murdoch University, Western Australia 6150.


Praziquantel was shown to have adverse effects on protoscoleces of Echinococcus granulosus in vitro. Exposure to one dose of praziquantel at a concentration of 10μg/ml caused protoscoleces to die within 12 to 15 days. Protoscolecidal effects were more marked when cultures were exposed to the drug continuously by the addition of multiple doses. On the basis of these observations, there is a need to reappraise the metacestocidal potential of praziquantel, particularly with regard to the development of new drug regimes employing multiple dose or sustained release schedules. Possible reasons for the reduced susceptibility of protoscoleces and juvenile worms to praziquantel observed in this study are discussed.

(Accepted July 02 1986)