Fleas resistant to capstar and frontline ?

I have treated my lab with both of these meds in the past 3 weeks and she still infested with fleas and develop flea dermatitis. I’m heading to the vet to lick up the oral prescription, any other suggestions ?

I think that visiting your vet is absolutely the correct thing to do.  Always be honest about what you have used so far, and WHEN, if you have some kind of record, in order to avoid risks e.g. of accidental overdose, or repeating of a drug that didn't seem to work.  It may be a good idea to let the vet weigh your dog, choose and administer the product, which ought remove the question of whether the product was a) appropriate and b) applied correctly.  Most of the time, a veterinary product applied correctly will resolve the issue.