How does Medifox act on ticks? - briefly
Medifox interferes with tick neurotransmission by blocking acetylcholinesterase activity, leading to rapid paralysis and mortality. Applied topically, it penetrates the exoskeleton and eliminates the parasite within hours.
How does Medifox act on ticks? - in detail
Medifox exerts its acaricidal effect through a combination of neurotoxic and metabolic disruption mechanisms. The active ingredient, a synthetic pyrazole derivative, penetrates the tick’s cuticle and reaches the central nervous system. Once inside, it binds to voltage‑gated sodium channels, prolonging their open state and causing uncontrolled neuronal firing. This leads to rapid paralysis and death.
Simultaneously, Medifox interferes with mitochondrial respiration. It inhibits complex I of the electron transport chain, reducing ATP production and inducing oxidative stress. Energy depletion compromises muscle function and impairs feeding behavior, further contributing to mortality.
The formulation includes a surfactant that enhances cuticular absorption, allowing effective delivery even to engorged specimens. Field studies show a dose‑dependent reduction in tick attachment rates, with complete eradication at concentrations above 0.5 % w/v within 24 hours.
Key points of action:
- Sodium‑channel agonism → sustained depolarization → paralysis.
- Mitochondrial complex I inhibition → ATP shortage → oxidative damage.
- Surfactant‑mediated cuticle penetration → rapid systemic exposure.
Resistance monitoring indicates low cross‑resistance with organophosphates, as the target sites differ. However, repeated sub‑lethal exposure may select for mutations in sodium‑channel genes, underscoring the need for rotation with alternative acaricides.