Cat flea medicine. The pill nitenpyram (Capstar) kills adult fleas on your cat within 30 minutes. It doesn't have any lasting effects, though. Spinosad (Comfortis) is a fast-acting chewable that ...

It's strictly and solely for fleas." Comfortis is one of two oral flea control products available for cats; the other is Capstar Flea Control Tablets. Unlike Capstar, which kills fleas for only 24 ...