How does Simparica work against ticks? - briefly
Simparica contains the oral acaricide sarolaner, which blocks GABA‑ and glutamate‑gated chloride channels in ticks, causing rapid paralysis and death. After absorption into the bloodstream, the drug reaches attached ticks and eliminates them within 24 hours.
How does Simparica work against ticks? - in detail
Simparica contains the active ingredient sarolaner, a member of the isoxazoline class. After oral administration, sarolaner is rapidly absorbed from the gastrointestinal tract, reaching peak plasma concentrations within 2–4 hours. The compound distributes systemically, exposing blood‑feeding ticks to therapeutic levels throughout the body.
The drug’s efficacy relies on selective inhibition of ligand‑gated chloride channels—specifically the γ‑aminobutyric acid (GABA)‑gated and glutamate‑gated channels of arthropod nervous systems. By blocking these channels, sarolaner prevents the influx of chloride ions, leading to uncontrolled neuronal excitation, paralysis, and death of the tick. Because the target receptors differ markedly from mammalian counterparts, toxicity to the host animal remains low.
Key pharmacokinetic features supporting tick control:
- Long half‑life (~10 days) maintains effective plasma concentrations for a month after a single dose.
- High oral bioavailability ensures consistent systemic exposure without the need for topical application.
- Broad spectrum activity covers multiple tick species, including Rhipicephalus sanguineus, Ixodes scapularis, and Dermacentor variabilis.
When a tick attaches and begins feeding, it ingests blood containing sarolaner. Within minutes, the drug reaches the tick’s nervous system, interrupting feeding behavior and causing rapid mortality. This mechanism also reduces the risk of pathogen transmission, as the tick is killed before it can transmit disease agents such as Ehrlichia or Babesia.
In summary, Simparica delivers a systemic, long‑acting isoxazoline that targets tick GABA and glutamate receptors, inducing paralysis and death shortly after attachment, thereby providing reliable monthly protection against a wide range of tick species.