I think the best thing to do is to call the vet who is caring for your cat and ask them, there may be reactions to medications, and a lot of things we need to consider. You have seen the fleas I take it, right now you don't want to be doing a lot of preventative things. I'll say a prayer for your sweet little one, it's a hard thing to go through and bad on the ones who love them, bless you for your concern and caring.