Overview of Fipronil and Methoprene (Frontline Plus®) for Dogs and Cats

Fipronil and methoprene, commonly known as Frontline Plus®, is used in the control and treatment of all stages of flea infestations and tick infestations in dogs and cats 

Fipronil is a phenylpyrazole antiparasitic agent and methoprene is an insect growth regulator. Combined together, fipronil and methoprene kill adult and larval fleas as well as flea eggs. All stages of ticks are also killed.

It works by interfering with the central nervous system of insects, resulting in death.

Fipronil and methoprene is a topical solution that collects in the oils of the skin and in the hair follicles. It is not absorbed into the body and does not circulate through the blood stream. Through the process of translocation, it is spread over the body in about 24 hours.

The effects of fipronil and methoprene lasts about 30 days and remains effective after bathing or swimming though shampooing should be avoided within 48 hours of application.

This drug is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

Brand Names or Other Names of Fipronil and Methoprene 

This drug is registered for use in animals only.

Human formulations: None

Veterinary formulations: Frontline Plus® (Merial)

Other veterinary formulations: Fipronil is also available without methoprene in Frontline Top Spot® and Frontline® Spray Treatment (Merial)

Uses of Fipronil and Methoprene for Dogs and Cats

Fipronil and methoprene is used in the control and treatment of all stages of flea infestations and tick infestations in dogs and cats.

It is also used for the treatment and control of chewing lice in dogs, puppies, kittens and cats.

Fipronil aids in the control of sarcoptic mange infestations in dogs.

It has also been used to treat Cheyletiellosis(Walking Dandruff Mite)in dogs and cats.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, fipronil and methoprene can cause side effects in some animals.

Fipronil and methoprene should not be used in animals with known hypersensitivity or allergy to the drug.

Fipronil and methoprene is a topical agent and temporary irritation at the site of application is possible.

This product is not recommended for use in debilitated or geriatric animals.

It is not recommended for use in puppies or kittens less than 8 weeks of age.

Spotted areas may appear wet or oily for up to 24hours.

Overdose is rare and no adverse effects have been reported even up to 5 times the dose.

How Fipronil and Methoprene is Supplied

Fipronil and methoprene is available in a topical solution. Each card contains either 3 or 6 pipettes that contain 9.8% fipronil and 8.8% methoprene.

Dosing Information of Fipronil and Methoprene for Dogs and Cats

Medication should never be administered without first consulting your veterinarian.

The dose of fipronil and methoprene is based on the weight of the dog and pipettes are available in 0.69 ml (for dogs up to 22 pounds), 1.36 ml (for dogs 23 to 44 pounds) and 2.7 ml (for dogs 45 to 88 pounds) and 4.02 ml (for dogs 89 to 132 pounds). One pipette is applied topically every 30 days.

For cats, pipettes are available in 0.52 ml and one pipette is applied once monthly.

The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian.