Vatinoxan does not reducecentral nervous system depression, as it is unable to cross the blood–brain barrier. However, it may influence the sedative effects of α2-adrenergic receptor agonists.[4]
Afixed-dose combination ofmedetomidine with vatinoxan (medetomidine/vatinoxan) is used to provide sedation whilst negating some of the negative cardiovascular effects of medetomidine.[4] This combination medication was approved in the US in 2022, and is sold under the brand name Zenalpha.[12]
Co-administration of vatinoxan and medetomidine improves recovery followingatipamezole administration in sheep and dogs.[4][13][14]
Vatinoxan binds to the α2-adrenergic receptor at a ratio of 105:1 over the α1-adrenergic receptor.[4] Vatinoxan appears to have no clinically relevant effect on the α1-adrenergic receptor based on a study in the horse and sheep.[15][4] Vatinoxan's lowlipid solubility, molecular weight, ionisation, and protein binding cause it to poorly antagonise the α2-adrenergic receptors in thecentral nervous system whilst selectively antagonising peripheral and cardiovascular receptors. These properties make vatinoxan unique to the other α2-adrenergic receptor antagonists.[4]
In a study on horses, vatinoxan administration was found to reduce medetomidine-induced sedation, which the authors hypothesised was due to altered clearance of medetomidine.[4][16] Conversely, a study in sheep reported that co-administration of vatinoxan and medetomidine enhanced sedation.[4][13]
Vatinoxan may also counteract the severe respiratory effects caused by α2-adrenergic receptor agonists in sheep.[4][17][18]
^Bennett R (September 2021). "Vatinoxan: a new development in the clinical use of α2-adrenoceptor agonists in dogs, part 1".Companion Animal.26 (8):176–181.doi:10.12968/coan.2021.0040.
^Bennett R (November 2021). "Vatinoxan: a new development in the clinical use of α2-adrenoceptor agonists in dogs, part 2".Companion Animal.26 (10):1–4.doi:10.12968/coan.2021.0073.
^abcdefghijklmLamont LA, Creighton CM (2024). "Sedatives and Tranquilizers". In Lamont L, Grimm K, Robertson S, Love L, Schroeder C (eds.).Veterinary Anesthesia and Analgesia, The 6th Edition of Lumb and Jones. Wiley Blackwell. pp. 338–344.ISBN978-1-119-83027-6.
^Pypendop BH, Honkavaara J, Ilkiw JE (2017). "Cardiovascular effects of dexmedetomidine, with or without MK-467, following intravenous administration in cats".Veterinary Anaesthesia and Analgesia.44 (1):52–62.doi:10.1111/vaa.12397.PMID27377604.
^Honkavaara JM, Restitutti F, Raekallio MR, Kuusela EK, Vainio OM (2011). "The effects of increasing doses of MK-467, a peripheral alpha 2-adrenergic receptor antagonist, on the cardiopulmonary effects of intravenous dexmedetomidine in conscious dogs".Journal of Veterinary Pharmacology and Therapeutics.34 (4):332–337.doi:10.1111/j.1365-2885.2010.01242.x.ISSN0140-7783.PMID20969603.
^Pypendop BH, Honkavaara J, Ilkiw JE (2017). "Cardiovascular effects of dexmedetomidine, with or without MK-467, following intravenous administration in cats".Veterinary Anaesthesia and Analgesia.44 (1):52–62.doi:10.1111/vaa.12397.PMID27377604.
^abAdam M, Raekallio MR, Vainio OM (2018). "Sedative effect of intramuscular medetomidine with and without vatinoxan (MK-467), and its reversal with atipamezole in sheep".Veterinary Anaesthesia and Analgesia.45 (6):788–793.doi:10.1016/j.vaa.2018.06.009.PMID30301665.
^Turunen H, Raekallio MR, Honkavaara JM, Restitutti F, Kallio-Kujala IJ, Adam M, et al. (2019). "Cardiovascular and sedation reversal effects of intramuscular administration of atipamezole in dogs treated with medetomidine hydrochloride with or without the peripheral α2-adrenoceptor antagonist vatinoxan hydrochloride".American Journal of Veterinary Research.80 (10):912–922.doi:10.2460/ajvr.80.10.912.ISSN0002-9645.PMID31556714.
^Pypendop BH, Ahokoivu H, Honkavaara J (2019). "Effects of dexmedetomidine, with or without vatinoxan (MK-467), on minimum alveolar concentration of isoflurane in cats".Veterinary Anaesthesia and Analgesia.46 (4):443–451.doi:10.1016/j.vaa.2019.02.004.PMID30982711.
^Hector RC, Rezende ML, Mama KR, Steffey EP, Knych HK, Hess AM, et al. (2017). "Effects of constant rate infusions of dexmedetomidine or MK-467 on the minimum alveolar concentration of sevoflurane in dogs".Veterinary Anaesthesia and Analgesia.44 (4):755–765.doi:10.1016/j.vaa.2016.12.058.PMID28734855.