i believe the preferred med for Tapeworm is praziquantel and there was a reputable seller on E-Bay last time i checked, if you are in U.S.
You can also buy from fish supply dealers online, just make sure its 100% prazi, there a few diff brands but the E-Bay seller was quite a bit cheaper.
also, megadose of Co-Q10 for 5-7 days iirc is a reccomendation of Hulda Clark . I tried and it didnt work for me but others have seen some results from it.
why do you suspect tapeworm? you might be better off trying a broader spectrum anthelmintic first until you know for sure.