Oral tablets you can buy from supermarket is Capstar. It works for both cats and dogs. It start killing fleas 30 minutes after taking and last 24 hours. But it's 24 hours only. It's a good one to use with spot treatment when cats and dogs already have a lot of fleas on them.

 

For dogs there is a oral tablets work for 30 days called Comfortis. It works very well but they  are only for dogs and not for cats.

 

But considering how hard to give cats tablets I understand the reason they didn't even bother making one for cats. It was almost impossible to give our Pillow a worming tablet. So it's good I use Revolution for them because it works for worms as well as flea.