Worms then fleas

My kitties came home today from getting spayed/neutered yesterday.

Hex was due today for a second dose of Drontal (I think) because he had roundworms. He had one 3 weeks ago and was supposed to take another one today.

But the clinic said he had fleas and recommended Revolution. If I give him Revolution, should I skip the pill?

Also, I didn't think either kitties had fleas, but they both had to have Capstar(?) prior to their surgery because of fleas. Could they have picked them up -at the clinic-?

A kitty can have just one or two and you think they are free of fleas.  I took in an orphaned kitten, he was too young for any of the pesticide treatments so I gave him several baths.  I thought I had gotten them all.  I took him for his first vet visit at 8 weeks, vet ran a flea comb through and found flea dirt.  By that time he was old enough for Frontline.  Fleas and worms go together.  They usually get tapeworms from fleas and that requires a different medication from the roundworms.

Absolutely give the dose of drontal.

I would also recommend regularly flea treatments to prevent future flea infestations as well as tapeworms.

So it is safe to give the Drontal and Revolution on the same day?

Yes, it's fine to give both.