Flumethrin

Flumethrin is a synthetic pyrethroid insecticide and acaricide used to control ectoparasites on livestock and companion animals, and in some crop protection products. It is formulated in various veterinary and agricultural preparations, including pour-on or spray treatments, powders, and collars that release the active ingredient over time.

Mode of action and properties: Flumethrin acts primarily on voltage-gated sodium channels in the nervous systems of insects and arthropods, prolonging channel opening and causing sustained nerve firing, paralysis, and death. It is lipophilic and tends to accumulate in fatty tissues, contributing to its residual activity in treated animals.

Applications and efficacy: It is effective against a range of ectoparasites, notably ticks and mites, and provides prolonged protection in certain formulations. In veterinary products, flumethrin is often used alone or in combination with other active ingredients to broaden activity against multiple pests.

Safety and environmental considerations: In mammals, flumethrin generally shows relatively low acute toxicity when used as directed, but can cause skin or eye irritation in some individuals and may produce neurological symptoms at high exposures. It is more toxic to aquatic organisms and some non-target invertebrates, so measures are needed to prevent release into water and to minimize impacts on beneficial insects. As with all pesticides, withdrawal times and proper handling should be followed.

Regulatory status: Approval and labeling vary by country. Flumethrin is registered for veterinary use in many jurisdictions in various formulations (topical, pour-on, collars) and is also found in some agricultural products. Ongoing resistance management and adherence to label instructions are important to maintain effectiveness and safety.