Capstar Oral Flea Treatment by Novartis is oral tablets containing Nitenpyram for the treatment of flea infestation on dogs, puppies, cats and kittens 4 weeks of age or older and 2 lbs or greater body weight. Fast acting-begins working within 30 minutes. A single dose should kill the adult fleas on your dogs within 4 hrs and within 6 hrs on your cat. Safe for use in pregnant or breeding animals. May be used as needed, as often as once per day, whenever you see fleas on your pet. 6 tablets.