Pharmacotherapeutic group: Ectoparasiticides, insecticides and repellents, permethrin combinations. ATCvet code: QP53AC54.
Pharmacodynamic properties
Dinotefuran is an insecticide. Its structure is derived from the neurotransmitter acetylcholine and acts on nicotinic acetylcholine receptors of the insect nerve synapse. Once bound to these receptors, the agonist action of repeated excitatory impulses kills the insect. Insects do not have to ingest dinotefuran, it kills by contact. Dinotefuran has low affinity to mammalian acetylcholine receptor sites.
Pyriproxyfen is a photostable insect growth regulator (IGR). It acts through contact, by mimicking the juvenile hormone, which regulates the moulting of insects from one life stage to the next. Pyriproxyfen stops the flea life cycle by both inducing premature oviposition and also suppressing yolk deposition in flea eggs, leading to the production of infertile eggs. Pyriproxyfen also blocks the development of juvenile stages (larvae and early (pharate) pupae) into adult emergence. This prevents infestation within the environment of the treated animal.
Permethrin is a synthetic pyrethroid. Pyrethroids act as neurotoxins on voltage-gated sodium channels by slowing their activation and inactivation properties. This results in hyperexcitability and death of the parasite. Permethrin is acaricide and insecticide. It also possesses repellent properties.
A synergistic effect was observed in vitro when dinotefuran was administered in conjunction with permethrin, leading to a faster onset of insecticidal activity in vivo. On the day of first treatment this veterinary medicinal product results in adequate flea adulticidal activity within 12 hours after application.
The anticipated clinical benefit resulting from a combination of dinotefuran with permethrin was demonstrated in one laboratory study on dogs which showed a prolongation of the duration of efficacy against C. canis fleas to 4 weeks.
Pharmacokinetic particulars
Following topical application, dinotefuran and pyriproxyfen are partially absorbed through the dog’s skin leading to systemic exposure. For permethrin, the plasma levels remain under the limit of quantification. The three active substances rapidly distribute over the body surface of the animal within the first day, with maximum concentrations obtained 3 days after the application. The three active substances were still measurable in different zones of the hair coat one month after treatment.
Environmental properties
The veterinary medicinal product should not enter water courses as it is dangerous for fish and other aquatic organisms. Do not contaminate ponds, waterways or ditches with the veterinary medicinal product or with used containers.