How does a flea and tick tablet work? - briefly
The tablet is swallowed, spreads an insecticide via the animal’s blood, and eliminates parasites when they attach and feed. Active compounds such as neonicotinoids or isoxazolines disrupt the nervous system of fleas and ticks, causing rapid paralysis and death.
How does a flea and tick tablet work? - in detail
The oral tablet is ingested, absorbed through the gastrointestinal tract within a few hours, and enters the bloodstream. Systemic circulation distributes the active compound to all tissues, including the skin and hair follicles where ectoparasites feed.
Once a flea or tick attaches and ingests blood, the medication reaches the parasite’s nervous system. Most formulations contain a neonicotinoid, an isoxazoline, or a spinosad derivative. These agents act as agonists or antagonists at insect‑specific ligand‑gated ion channels:
- Neonicotinoids bind to nicotinic acetylcholine receptors, causing persistent activation, neuronal overstimulation, and paralysis.
- Isoxazolines block γ‑aminobutyric acid (GABA)–gated chloride channels, preventing inhibitory signaling and leading to uncontrolled excitation.
- Spinosad disrupts the nicotinic acetylcholine receptor complex, resulting in hyperexcitation and eventual death.
The selective affinity for arthropod receptors over mammalian counterparts provides a wide safety margin. After ingestion, the parasite’s metabolic processes cannot detoxify the compound efficiently, so rapid onset of toxicity follows within minutes to hours.
Efficacy persists because the drug remains in the host’s plasma at therapeutic concentrations for several weeks. Continuous exposure ensures that newly acquired fleas and feeding ticks encounter lethal doses before they can reproduce or transmit pathogens. Excretion occurs primarily via the kidneys, with a small fraction eliminated in feces, limiting environmental accumulation.
Key pharmacological steps:
- Oral administration → gastrointestinal absorption.
- Systemic distribution → steady plasma levels.
- Parasite blood meal → drug delivery to parasite.
- Binding to insect‑specific ion channels → neuronal disruption.
- Paralysis → death of flea or tick.
The result is rapid elimination of existing infestations and sustained protection against future bites for the duration specified by the product’s pharmacokinetic profile.