How do tablets for ticks work? - briefly
Oral tick-control tablets deliver an acaricide that is absorbed into the animal’s bloodstream and kills attached ticks by disrupting their nervous system. The active ingredient remains effective for several weeks, providing systemic protection after a single dose.
How do tablets for ticks work? - in detail
Oral acaricide tablets are formulated to eliminate ticks after the host ingests the dose. The active compound—commonly a macrocyclic lactone (e.g., afoxolaner, fluralaner) or an isoxazoline—enters the gastrointestinal tract, is absorbed into the bloodstream, and distributes throughout the body’s tissues and fluids.
Once in circulation, the molecule reaches the tick’s feeding site. Ticks attach to the host’s skin, insert their mouthparts, and ingest blood. The drug present in the host’s plasma is taken up with the blood meal. Inside the tick, the compound binds to ligand‑gated chloride channels (GABA‑gated or glutamate‑gated) and disrupts normal neuronal signaling. This leads to uncontrolled neuronal firing, paralysis, and death of the parasite within hours to a few days, depending on the species and life stage.
Key pharmacokinetic steps include:
- Absorption: Rapid uptake from the intestinal wall, achieving peak plasma concentration within 2–4 hours for most products.
- Distribution: High affinity for plasma proteins, enabling prolonged presence in the bloodstream; half‑life ranges from 12 days (isoxazolines) to several weeks (some macrocyclic lactones).
- Metabolism and excretion: Primarily hepatic metabolism; metabolites are excreted via urine and feces, minimizing residue in the host.
The therapeutic window is designed to maintain effective concentrations for at least one month, covering the typical tick activity period. Dosage calculations are based on body weight to ensure sufficient plasma levels without exceeding safety thresholds. Resistance management strategies recommend rotating products with different modes of action when tick populations show reduced susceptibility.
In summary, oral tick tablets function by delivering a systemic neurotoxic agent that, after absorption and distribution, is ingested by feeding ticks, causing rapid paralysis and mortality, thereby providing sustained protection for the host.