Drug Information for COMFORTIS (spinosad) Chewable Tablets (Elanco Animal Health Co): Effectiveness:

In a well-controlled laboratory study, COMFORTIS chewable tablets began to kill fleas 30 minutes after administration and demonstrated 100% effectiveness within 4 hours. COMFORTIS chewable tablets kill fleas before they can lay eggs. If a severe environmental infestation exists, fleas may persist for a period of time after dose administration due to the emergence of adult fleas from pupae already in the environment. In field studies conducted in households with existing flea infestations of varying severity, flea reductions of 98.0% to 99.8% were observed over the course of 3 monthly treatments with COMFORTIS chewable tablets. Dogs with signs of flea allergy dermatitis showed improvement in erythema, papules, scaling, alopecia, dermatitis/pyodermatitis and pruritus as a direct result of eliminating the fleas.