Understanding Bravecto: An Overview
What is Bravecto?
The Active Ingredient: Fluralaner
Fluralaner, the sole active compound in Bravecto tablets, belongs to the isoxazoline class of ectoparasiticides. After oral administration, the molecule is rapidly absorbed into the bloodstream and distributes throughout the canine or feline body. Its high plasma protein binding and prolonged elimination half‑life (up to 12 weeks) maintain therapeutic concentrations that persist in the host’s skin and hair follicles.
The insecticidal effect originates from selective inhibition of ligand‑gated chloride channels (GABA‑ and glutamate‑gated) in fleas and ticks. By blocking these channels, fluralaner disrupts neuronal inhibition, causing uncontrolled nerve firing, paralysis, and death. Parasites ingest the drug only when feeding on treated animals; the systemic nature of the treatment eliminates the need for direct contact with the medication.
Key pharmacological characteristics:
- Oral bioavailability exceeds 80 % in dogs and cats.
- Peak plasma levels occur within 2–4 hours post‑dose.
- Effective concentrations remain above the minimum lethal dose for fleas and ticks for up to 12 weeks.
- No significant accumulation in non‑target tissues; metabolism primarily involves hepatic pathways with renal excretion of metabolites.
These properties enable a single monthly or quarterly tablet to provide continuous protection against both adult and immature stages of common flea and tick species.
Formulations and Administration
Bravecto tablets contain the active ingredient fluralaner, a member of the isoxazoline class. The formulation is a solid, chewable tablet designed for rapid dissolution in the oral cavity, allowing systemic absorption through the gastrointestinal tract. Once absorbed, fluralaner binds to ligand‑gated chloride channels in arthropod nerve cells, producing prolonged paralysis and death of fleas and ticks.
The product is supplied in weight‑specific dose strengths: 14 mg, 28 mg, 56 mg, and 112 mg. Each strength corresponds to a defined range of animal body weight, ensuring that the administered amount delivers the target plasma concentration for at least 12 weeks. The tablet must be given whole, without crushing or splitting, to preserve the integrity of the coating that protects the active ingredient from premature degradation.
Administration guidelines require a single oral dose administered with food to enhance bioavailability. Dogs may receive the tablet on any day of the week; the next dose is scheduled 84 days later. For cats, the same 12‑week interval applies, with dose strengths adjusted for feline weight categories. The medication is contraindicated in animals with known hypersensitivity to isoxazolines or any component of the tablet matrix.
Storage recommendations specify a temperature range of 2 °C to 30 °C, protection from moisture, and retention of the original packaging until use. Unused tablets retain potency for the duration indicated on the label, provided the storage conditions are maintained.
The Mechanism of Action: How Bravecto Works
Absorption and Distribution
Oral Administration and Bioavailability
Bravecto tablets are administered orally as a chewable dose calibrated to the animal’s body weight. The tablet is swallowed whole or chewed, allowing rapid entry into the gastrointestinal tract. Dissolution occurs within minutes, and the active molecule, fluralaner, is absorbed across the intestinal epithelium.
Systemic absorption yields a bioavailability of approximately 80 % in dogs and 70 % in cats, measured by plasma concentrations after a single dose. Peak plasma levels are reached between 2 and 8 hours post‑administration, after which the compound distributes widely into skin, hair follicles, and peripheral tissues. High protein binding (≈99 %) extends the circulatory half‑life to 12 weeks, sustaining therapeutic concentrations without repeat dosing.
Key pharmacokinetic points:
- Absorption: Rapid gastrointestinal uptake; minimal first‑pass metabolism.
- Distribution: Uniform dissemination to dermal layers where ectoparasites feed.
- Elimination: Predominantly hepatic metabolism with biliary excretion; renal clearance negligible.
The prolonged systemic presence of fluralaner ensures continuous exposure of feeding fleas and ticks to lethal concentrations, providing month‑long protection from a single oral tablet.
Systemic Distribution within the Animal
After oral administration, the tablet dissolves in the gastrointestinal tract and the active ingredient, fluralaner, is absorbed into the bloodstream. Peak plasma concentrations occur within 2–4 hours, reflecting rapid uptake from the gut lining.
In plasma, fluralaner binds extensively to albumin, achieving a free fraction of less than 5 %. This high protein binding prolongs systemic exposure and reduces renal clearance. The compound’s lipophilic structure facilitates passage across cell membranes, allowing distribution into peripheral tissues.
Targeted tissues include the skin’s dermal layer, hair follicles, and sebaceous glands, where adult fleas and feeding ticks acquire the drug through blood meals. Concentrations in these compartments remain above the lethal threshold for ectoparasites for at least 12 weeks, ensuring continuous protection.
Key pharmacokinetic characteristics:
- Half‑life: approximately 15 days in dogs, 30 days in cats.
- Volume of distribution: 3–5 L/kg, indicating extensive tissue penetration.
- Elimination: primarily hepatic metabolism with minimal urinary excretion.
Sustained systemic presence eliminates the need for repeated applications, as the drug continuously circulates and reaches the sites where parasites feed, delivering lethal doses each time they ingest blood.
Targeting Fleas and Ticks
Fluralaner’s Effect on Parasites
Fluralaner, the active ingredient in Bravecto tablets, targets the nervous system of ectoparasites. It binds to ligand‑gated chloride channels that normally respond to gamma‑aminobutyric acid (GABA) and glutamate. Blockage of these channels prevents inhibitory neurotransmission, leading to uncontrolled neuronal firing, paralysis, and death of fleas and ticks.
After oral administration, fluralaner is rapidly absorbed into the bloodstream and distributes throughout the animal’s tissues. Its high plasma protein binding and long elimination half‑life (approximately 12 weeks in dogs) ensure sustained concentrations that remain lethal to parasites for an extended period. Because the drug is systemic, parasites are exposed when they feed on the host’s blood, eliminating the need for direct contact with the medication.
Key pharmacological effects include:
- Rapid onset: Parasite mortality occurs within hours of feeding.
- Broad spectrum: Effective against adult fleas, all life stages of ticks, and several mite species.
- Resistance mitigation: Unique mode of action reduces cross‑resistance with older insecticides.
- Safety profile: Selective affinity for arthropod receptors limits adverse effects in mammals.
The combination of systemic delivery, prolonged plasma levels, and precise neural targeting underpins the efficacy of Bravecto tablets in controlling flea and tick infestations.
Neurotoxic Action
Bravecto tablets contain the active compound fluralaner, a member of the isoxazoline class. Fluralaner targets the nervous system of fleas and ticks by binding to ligand‑gated chloride channels that normally regulate neuronal excitability.
- The drug attaches to γ‑aminobutyric acid (GABA)‑gated chloride channels, preventing the influx of chloride ions that would normally hyperpolarize the neuron.
- It also blocks glutamate‑gated chloride channels, a second inhibitory pathway unique to arthropods.
- Inhibition of both channels removes the primary inhibitory controls, causing continuous depolarization and uncontrolled firing of nerve impulses.
- Sustained neuronal hyperactivity leads to loss of motor coordination, paralysis, and eventual death of the parasite.
Because the affected channels are absent or structurally different in mammals, the neurotoxic effect remains selective for ectoparasites while posing minimal risk to the host animal. The prolonged systemic presence of fluralaner after oral administration ensures that any feeding flea or tick encounters the neurotoxic agent, resulting in rapid incapacitation.
Duration of Efficacy
Sustained Protection
Bravecto tablets deliver an active ingredient that enters the bloodstream after oral administration and remains at therapeutic levels for an extended period. The compound is absorbed rapidly, binds to plasma proteins, and is distributed throughout the skin and hair follicles where fleas and ticks feed.
The drug’s elimination half‑life exceeds several weeks, allowing a steady concentration that exceeds the minimum inhibitory dose for both adult fleas and tick species. As parasites ingest blood containing the compound, they are killed before they can reproduce or transmit disease.
Key aspects of sustained protection:
- Single dose provides continuous efficacy for up to 12 weeks against fleas and up to 8 weeks against ticks.
- Systemic action eliminates the need for topical re‑application.
- Consistent plasma levels reduce the risk of breakthrough infestations.
- Long‑lasting effect improves owner compliance by minimizing treatment frequency.
The prolonged exposure profile ensures that newly acquired parasites are intercepted throughout the entire dosing interval, delivering reliable control without gaps in coverage.
Why it Lasts so Long
Bravecto tablets contain fluralaner, a member of the isoxazoline class that interferes with the GABA‑gated chloride channels of fleas and ticks. The molecule’s chemical structure gives it high lipophilicity, allowing rapid penetration into the animal’s skin and hair follicles where parasites feed. Once absorbed, fluralaner binds strongly to plasma proteins, which slows its clearance from the bloodstream and creates a prolonged distribution phase.
Key pharmacokinetic factors that extend efficacy:
- Long elimination half‑life (approximately 15 days in dogs, 12 days in cats) maintains plasma concentrations above the lethal threshold for parasites throughout the dosing interval.
- High plasma protein binding (> 99 %) reduces renal filtration and hepatic metabolism, limiting rapid excretion.
- Persistent tissue reservoirs in skin and subcutaneous fat act as slow‑release depots, supplying a steady supply of active ingredient to the parasite’s feeding site.
- Oral formulation with a solid matrix protects the active compound from premature degradation in the gastrointestinal tract, ensuring maximal absorption.
The combination of these mechanisms results in a drug level that remains effective for up to 12 weeks after a single administration, eliminating the need for frequent re‑treatment while providing continuous protection against both fleas and ticks.