Information for Veterinarians
A new entry ingredients tick and flea control is now available from Novartis Animal Health US, Inc.
Parastar™ Plus contains two active ingredients, fipronil and cyphenothrin. Fipronil is the most successful adulticide in small veterinary medicine due to its broad spectrum of activity, excellent safety profile and its long residual performance. The efficacy and safety of the molecule has been well established since its development in the mid-1990s and is still widely used today in Frontline® Top Spot®.* For more detailed information, view the fact sheet.
How Does It Work?
Parastar Plus's mechanism of action is complex. Fipronil interacts with gamma aminobutyric acid (GABA)-gated and glutamate-gated chloride channels in the nervous systems of target species. It blocks inhibitory nerve transmission in susceptible ectoparasites, leading to hyperexcitability and death. Cyphenothrin is a pyrethroid that works by interfering with sodium transport in insect nerve cells, resulting in the paralysis and death of target species.
Indications
Fipronil is an ectoparasiticide that is effective against insects and some members of the order Acarina (e.g., ticks and mites). The two ectoparasites most often targeted by pet formulations are fleas and ticks. Fipronil is also active against mites that cause sarcoptic mange and chewing lice.
Chemical and Physical Properties
Fipronil's high lipophilicity and low water solubility play an important role in its residual efficacy. Fipronil is much less soluble in water than the active ingredients in competitive products, so it is less likely to be washed off.
Efficacy
- Starts killing ticks and fleas in as little as 1 hour and continues to kill for a month.
- Kills ticks (brown dog ticks, deer ticks, American dog ticks, lone star ticks), including those that may transmit Lyme disease, Rocky Mountain spotted fever, ehrlichiosis, babesiosis, anaplasmosis and hepatozoonosis.
- Kills adult fleas.
- Kills chewing lice.
- Controls mites that may cause sarcoptic mange.
Product Uses
Parastar Plus can be used on dogs and puppies 12 weeks old and older. Do not use on cats.
Pet owners should be reminded to
- Know the exact weight of the pet and use the appropriate dose for that size animal.
- Read and follow label directions on the product package.
- Make sure to use the appropriate product for the pet. It is especially important to avoid using a dog product on a cat.
- Check with a veterinarian before using a flea and tick product on a debilitated, aged or medicated pet.


