CAPSTAR flea tablets for dogs (nitenpyram) is a fast-acting flea treatment tablet that starts killing fleas in only 30 minutes. A single dose of CAPSTAR dog flea medicine kills 90% of adult fleas within 4 hours for dogs. Pet parents can give this oral flea treatment and watch the dead fleas fall off your pet. CAPSTAR flea tablets are available for dogs and puppies 25.1-125 pounds, and 4 weeks of age or older.