My cat keeps vomiting.

My three or four month old indoor cat Jasper (formally known as Nomers) got in the trash last night (Sunday, July 14th) and dug a piece of slightly spicy chicken out and began to eat it, I got it away from him as soon as I noticed he was in the trash, threw it back into the garbage bag and tied it shut. It was slightly spicy to me, but I don't know how spicy it would be to him.

Then this afternoon I dropped my empty plate that had had a pepperoni hot pocket on it and he ran over and  licked the sauce off of it before I could get it away from him. He vomited twice already, is it from the spicy chicken the hot pocket or a combination of the two? And what should I do to make him feel better?

Onions and to a lesser extent garlic are toxic to cats. Other spices might upset his stomach. If he vomits again, I would seriously consider a vet visit. Is he vomiting food or just liquid? Any foaming at the mouth? Any lethargy or signs of pain? I'm not sure what you can do to help him. I don't know of any safe OTC tummy soothers for cats.

Sounds very much like he's just eaten foods he shouldn't have and that didn't agree with him. If he's acting normally otherwise, I'd give it 24 hours before taking him to see the vet. If he's very lethargic or sitting in a "meatloaf" position with his head down or drooling, he's in pain and very nauseous, and if he's like that in the morning, I'd get him to the vet.

Well I found out he actually has roundworms, my mom gave him some worm medicine we got for one of the other cats, how long does it take to start working?