(S)-Methoprene, Fipronil

Form: Spot-on solution · Pack size: PK 1

Dogs

This product can cause mucous membrane, skin and eye irritation. Therefore, contact of the product with mouth, skin and eyes should be avoided. People with a known hypersensitivity to insecticides or alcohol should avoid contact with the product.

In the absence of available data, the product should not be used on puppies less than 8 weeks old and/or weighing less than 2 kg. Do not use on sick (e.g. systemic diseases, fever) or convalescent animals.

• Legal category: AVM-GSL
• Marketing authorisation holder: KRKA, d.d., Novo mesto Šmarješka cesta 6 8501 Novo mesto Slovenia Further information Pharmacotherapeutic group: Ectoparasiticides for topical use. ATCvet code: QP53AX65 Fipronil is an insecticide and acaricide belonging to the phenylpyrazole family. It acts by interacting with ligand-gated chloride channels, in particular those gated by the neurotransmitter gamma-aminobutyric acid (GABA), thereby blocking pre- and postsynaptic transfer of chloride ions across cell membranes. This results in uncontrolled activity of the central nervous system and death of insects or acarines. Fipronil kills fleas within 24 hours and ticks (Dermacentor reticulatus, Dermacentor variabilis, Rhipicephalus sanguineus, Ixodes scapularis, Ixodes ricinus, Haemaphysalis longicornis, Haemaphysalis flava, Haemaphysalis campanulata) and lice within 48 hours postexposure. (S)-Methoprene is an insect growth regulator (IGR) of the class of compounds known as juvenile hormone analogues that inhibit the development of immature stages of insects. This compound mimics the action of juvenile hormone and causes impaired development and death of the developing stages of fleas. The on-animal ovicidal activity of (S)-methoprene results from either direct penetration of the eggshell of newly laid eggs or from absorption through the cuticle of the adult fleas. (S)methoprene is also effective in preventing flea larvae and pupae from developing, which prevents contamination of the environment of the treated animals with the immature stages of fleas. Studies of metabolism of fipronil have demonstrated that the major metabolite is the sulfone derivative of fipronil. (S)-methoprene is extensively degraded into carbon dioxide and acetate that are subsequently incorporated into endogenous materials. The pharmacokinetic profiles after topical application of fipronil and (S)-methoprene in combination were studied in dogs in comparison to intravenous dosing of fipronil or (S)-methoprene alone. This established absorption and other pharmacokinetic parameters. The topical application resulted in low systemic absorption of fipronil (11%) with a mean maximum concentration (Cmax) of approximately 35 ng/ml fipronil and 55 ng/ml of fipronil sulfone in plasma. Fipronil is extensively metabolised to fipronil sulfone after topical administration. Plasma concentrations of (S)-methoprene were below the limit of quantitation (20 ng/ml) in dogs after topical application. Both (S)-methoprene and fipronil, together with its major metabolite, are welldistributed in the hair/coat of a dog within one day after application. The concentrations of fipronil, fipronil sulfone and (S)-methoprene in the hair/coat decrease with time and are detectable for at least 60 days after dosing. Parasites are killed through contact rather than systemic exposure. No pharmacological interaction between fipronil and (S)-methoprene was noted.
• MA number: Fleascreen Combo Spot On for Dogs Small Vm 01656/4125 Fleascreen Combo Spot On for Dogs Medium Vm 01656/4126 Fleascreen Combo Spot On for Dogs Large Vm 01656/4127 Fleascreen Combo Spot On for Dogs Extra Large Vm 01656/4128

The information on this page is provided for general guidance only and does not replace the advice of a qualified veterinary surgeon. Always follow the directions provided on the product packaging and by your veterinary practice. If your animal's condition does not improve, worsens, or any side effects occur, contact your veterinary surgeon immediately.