Start Frontline on kitten?

I use Frontline Plus as a preventative on my 3yo kitty and my dog. My new kitten, Blue, is now 8 weeks old, and I'm wondering if I can start using it on her as well. The box says it's for cats 8 weeks through adult. She came to me last week with a URI, but she seems to be much better now. Do you think there's any reason I need to call the vet before starting her on the Frontline?

It's always best to check with the vet first when in doubt.