My 8 week old kitten has tape worms. Weird things are happening! Not sure what to do! HELP!!?

I came home today and noticed that my new 8 week old kitty had small rice shaped things around his . Called the vet, took him in, and they did a fecal sample and say he has tape worms. They gave me Drontal to give him 1/2 a pill. We went out and when I came home I noticed a terrible smell. He had poop stuck all around the outside of his . I have a 4 year old and am afraid to let the kitty sleep in our room (where he normally sleeps). I also notice some sort of liquid drippings on the floor coming from where he had been standing or sitting. I don't know what that is!?!? This whole thing is grossing me out, and I don't know what to do. How long does it take the pill to start working? What happens when it does start? Are these side effects from the pill that he is having? And my 1 yr old cat is terrorizing the little one too. Kitten stands up for himself and sometimes starts the fights but, I am afraid that my big boy is gonna hurt my little boy. Anything would help!!!