Frontline suddenly not working

I'm taking my baby to the vet tomorrow and they recommend comfortis. After reviewing it, no way. It seems too dangerous. Would revolution be better? Shes an indoor cat.

IMHO, Advantage (Bayer) is the safest and best, always did do better than Frontline.  They now have Advantage II which adds another product to kill larvae and not just adults.  It is so safe that you can apply as often as once a week in seriously severe flea infestations.  The product is the same between Advantage for Dogs and Advantage for Cats.  All that's different is the size of the packaged individual doses.  The dose is determined by the weight of the animal, be it dog or cat.  The same thing is true of Frontline.