We are lucky enough to have a vet who is a member on another forum I belong to. She said the only over the counter tapeworm medication that is safe and effective has to contain praziquantel.
Farnum makes a product called D-Worm that you can buy without a prescription. The package says not for use on puppies under four weeks of age, though. How old are the puppies?
I believe Petco has D-Worm. KV Vet also carries it for a lot less.
http://www.kvvet.com/KVVet/productr....FBD238EA8FA470