Pharmacotherapeutic group: ectoparasiticides, insecticides and repellents, pyrethrins and pyrethroids, Flumethrin combinations. ATCvet code: QP53AC55
Imidacloprid is an ectoparasiticide belonging to the chloronicotinyl group of compounds. Chemically, it can be classified as a chloronicotinyl nitroguanidine. Imidacloprid is active against larval flea stages, adult fleas and lice. In cats, activity against C.felis starts immediately after application of the collar. In dogs, activity against C. felis starts immediately after application of the collar whereas adequate efficacy against C. canis starts within one week after application of the collar. In addition to the indications listed under the 'Uses' section, an activity against Pulex irritans fleas has been demonstrated.
Imidacloprid has a high affinity for the nicotinergic acetylcholine receptors in the post-synaptic region of the central nervous system (CNS) of the flea. The ensuing inhibition of cholinergic transmission in insects results in paralysis and death. Due to the weak nature of the interaction with mammalian nicotinergic receptors and the postulated poor penetration through the blood-brain barrier in mammals, it has virtually no effect on the mammalian CNS. Imidacloprid has minimal pharmacological activity in mammals.
Flumethrin is an ectoparasiticide of the synthetic pyrethroid group. According to current knowledge the synthetic pyrethroids interfere with the sodium channel of nerve cell membranes, resulting in a delay in repolarisation of the nerve and finally killing of the parasite. In studies on structure-activity relationship of a number of pyrethroids, interference with receptors of a certain chiral conformation was noted thereby causing a selective activity on ectoparasites. No anti-cholinesterase activity was noted with these compounds. Flumethrin is responsible for the product’s acaricidal activity and also prevents production of fertile eggs by its lethal effect on female ticks. In an in-vitro study 5 to 10 % of Rhipicephalus sanguineus ticks exposed to a sublethal dose of 4 mg flumethrin/L laid eggs which had a modified appearance (shrivelled, dull and dry) indicating a sterilising effect.
In addition to the indications listed under ‘Uses’ section, activity has been demonstrated in cats against Ixodes hexagonus and the non-European tick species Amblyomma americanum and in dogs against I. hexagonus, I. scapularis and the non-European tick species Dermacentor variabilis and the Australian paralysis tick I. holocyclus. The product provides repellent (anti-feeding) activity against the claimed ticks, thus preventing repelled parasites from taking a blood meal and thereby indirectly aids in the reduction of the risk of Vector-Borne Disease transmission.
In cats, indirect protection against the transmission of Cytauxzoon felis (transmitted by Amblyomma americanum ticks) has been shown in one laboratory study in a small number of animals at one month after treatment, thereby reducing the risk of diseases caused by this pathogen under the conditions of this study. In dogs, in addition to the pathogens listed under 'Uses' section, indirect protection against the transmission of Babesia canis canis (by Dermacentor reticulatus ticks) has been shown in one laboratory study at day 28 after treatment, and indirect protection against the transmission of Anaplasma phagocytophilum (by Ixodes ricinus ticks) has been shown in one laboratory study at 2 months after treatment, thereby reducing the risk of diseases caused by these pathogens under the conditions of these studies.
Data of two clinical field studies performed in Leishmania infantum endemic areas indicate a significant reduction in the risk of Leishmania transmission by sand flies in treated dogs compared to non-treated dogs, while the efficacy of the product in the prevention of sandfly bites has not been established. The influence of shampooing or water immersion regarding the transmission of canine leishmaniosis has not been examined.
The collars were able to improve the Sarcoptes scabiei infestation in pre-infested dogs leading to a full cure after three months.
Cats and Dogs: Both active ingredients are slowly and continuously released in low concentrations from the polymer matrix system of the collar towards the animal. Both actives are present in the cat’s or dog’s haircoat in acaricidal/insecticidal concentrations during the entire efficacy period. The active substances spread from the site of direct contact over the entire skin surface. Target animal overdose and serum kinetic studies have established that imidacloprid reached the systemic circulation transiently while flumethrin was mostly not measurable. Oral absorption of both active substances is not relevant for the clinical efficacy.