How does Bravecto work against fleas? - briefly
Bravecto contains fluralaner, a systemic insecticide that blocks GABA‑gated chloride channels in fleas, leading to rapid paralysis and death. After oral administration, the compound spreads through the bloodstream to the skin, providing continuous protection for up to 12 weeks.
How does Bravecto work against fleas? - in detail
Bravecto contains the isoxazoline compound fluralaner, which targets the nervous system of adult fleas. After oral administration, the drug is rapidly absorbed from the gastrointestinal tract and distributed through the bloodstream to skin tissues, where fleas feed. Fluralaner binds to ligand‑gated chloride channels that are normally activated by γ‑aminobutyric acid (GABA) and glutamate. By blocking these receptors, the insect’s neuronal inhibition is lost, causing uncontrolled excitation, muscle tremors, paralysis, and death within hours of contact.
Key pharmacological features:
- Absorption: peak plasma concentrations occur 2–4 hours post‑dose; bioavailability exceeds 80 %.
- Distribution: systemic circulation delivers the compound to all skin surfaces; concentrations remain therapeutic for up to 12 weeks.
- Mode of action: irreversible antagonism of GABA‑ and glutamate‑gated chloride channels prevents inhibitory neurotransmission in fleas.
- Kill time: 90 % of adult fleas are eliminated within 8 hours; complete eradication typically achieved by 24 hours.
- Residual effect: sustained plasma levels maintain efficacy against newly infesting fleas throughout the dosing interval.
Safety data indicate a high margin of tolerance in dogs weighing 1.5 kg or more. The product is contraindicated in animals with known hypersensitivity to isoxazolines or in puppies under 8 weeks of age. Liver metabolism via cytochrome P450 enzymes produces inactive metabolites that are excreted primarily in the feces.
Resistance monitoring shows low incidence of cross‑resistance with other ectoparasitic classes, owing to the distinct binding site of fluralaner. Regular veterinary assessment ensures appropriate dosing and early detection of any adverse reactions.