Pharmacodynamic properties
Tigolaner belongs to the chemical class of bispyrazoles. Tigolaner acts as a potent inhibitor of the neurotransmitter gamma-aminobutyric acid (GABA) receptor. Tigolaner exhibits higher functional potency to block insect/acarine receptors compared to mammalian receptors in vitro. It is an acaricide and insecticide and is efficacious against ticks (Ixodes ricinus, I. holocyclus), fleas (Ctenocephalides felis), and mites (Notoedres cati, Otodectes cynotis) on cats.
Fleas already on the animal prior to administration are killed within 12 hours. For newly infecting fleas the onset of efficacy is within 8 hours for 2 months after product administration and within 24 hours afterwards. Fleas and ticks must attach to the host and start feeding in order to be exposed to tigolaner. Ixodes ricinus ticks on the animal prior to administration are killed within 24 hours. Ixodes ricinus ticks newly infested are killed within 48 hours for 13 weeks.
Emodepside is a semi-synthetic compound belonging to the chemical group of depsipeptides. It is active against all stages of roundworms (ascarids and hookworms). In this product, emodepside is responsible for the efficacy against Toxocara cati, Toxascaris leonina, Ancylostoma tubaeforme, Aelurostrongylus abstrusus and Troglostrongylus brevior.
It acts at the neuromuscular junction by stimulating presynaptic receptors belonging to the secretin receptor family which results in paralysis and death of the parasites.
Praziquantel is a pyrazinoisoquinoline derivative effective against the tapeworms Dipylidium caninum, and Taenia taeniaeformis.
Praziquantel is rapidly adsorbed via the surface of the parasites and acts primarily by changing the Ca++ permeability of the parasite membranes. This results in severe damage to the parasite integument, contraction and paralysis, disruption of metabolism and finally leads to the death of the parasite.
Pharmacokinetic particulars
After single topical administration of the product to cats, maximum tigolaner plasma concentrations of 1.35 mg/L were reached 12 days after dosing. Tigolaner plasma concentrations declined slowly with a mean half-life of 24 days. Emodepside reached maximum plasma concentrations of 0.044 mg/L 1.5 days after dosing. Emodepside plasma concentrations declined with a mean half-life of 14.5 days. Praziquantel reached maximum plasma concentrations of 0.048 mg/L already 5 hours after dosing. Praziquantel plasma concentrations declined with a mean half-life of 10 days. Individual variation in plasma concentrations and half-life was observed for all three substances. For tigolaner, a significant increase in half-life following repeated dosing was shown resulting in accumulation of tigolaner after 4 consecutive treatments in cats.
Tigolaner and emodepside are poorly metabolized and mainly excreted in the faeces. Renal clearance is the minor route of elimination. Praziquantel undergoes substantial hepatic metabolism and only traces are excreted equally via urine and faeces.