No, parasite drugs do not cause scattering....they kill parasites.

Niclosamide kills tapeworms & Mebendazole kills roundworms in the GI tract only. 

When adult parasites are killed, some of their released eggs & larva might escape from the intestines into the bloodstream & migrate, encyst, or nest throughout the body.

For the possibility of any scattered eggs & larva, followup treatment with Albendazole is always recommended!  It's a systemic drug that kills eggs, larva, & cysts throughout the body.