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Drug Details

  • Drug Name: Capstar
  • Common Name: Capstar®
  • Drug Type: Parasiticide
  • Used For: Treatment of adult fleas
  • Species: Dogs, Cats
  • Administered: Tablet
  • How Dispensed: Prescription only
  • FDA Approved: Yes

General Description


Nitenpyram is used to kill adult flea infestations on your pet. It works very fast and begins acts on the adult fleas’ nervous system within 30 minutes, killing them all within 4-6 hours. It is useful in the case of kenneling, showing, and traveling with pets, or to use in conjunction with a flea sterilant such as monthly Program or Sentinel. It does not act on immature fleas, eggs, or larvae, as they do not take a bloodmeal.


How It Works


After your cat or dog takes the Capstar tablet, the Nitenpyram is absorbed into the bloodstream very quickly. Once a flea takes a bloodmeal from your pet, they ingest enough of the drug to kill them.


Nitenpyram is a neonicotinoid, meaning it is similar to another pesticide nicotine. It acts on the flea central nervous system by binding to acetylcholin receptors. Acetylcholine is an essential neurotransmitter, and blockage of the receptor interferes with the passage of nerve signals and leads to impairment of the insect’s central nervous system.


Storage Information


Keep in a seal package at room temperature.


Missed Dose?


If you miss a dose, or are unsure a dose was given or swallowed, a second pill may be given safely.


Side Effects and Drug Reactions


Nitenpyram may result in these side effects:


  • Mild itchiness due to the dying fleas
  • Stomach upset


Nitenpyram does not appear to react with any drugs.



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