Vet Med - Czech, 2025, 70(12):427-431 | DOI: 10.17221/47/2025-VETMED

Effect of vatinoxan co-administered with medetomidine on intraocular pressure and pupil diameter in healthy dogsOriginal Paper

P Rauser ORCID..., M Mrazova ORCID..., A Sabatova, K Jiraskova
Department of Surgery and Orthopedics, Small Animal Clinic, Faculty of Veterinary Medicine, University of Veterinary Sciences, Brno, Czech Republic

Medetomidine, an alpha-2 adrenoreceptor agonist, is used for sedation. This study aimed to determine the influence of the alpha-2 adrenoreceptor antagonist vatinoxan, co-administered with medetomidine, on healthy dogs’ intraocular pressure (IOP) and pupil diameter (PD). A prospective, randomised, masked clinical study was performed. A total of 40 conscious dogs were allocated to one of two groups: medetomidine 0.01 mg/kg with vatinoxan 0.2 mg/kg intravenously (MV-group, n = 20) or medetomidine 0.01 mg/kg intravenously (M-group, n = 20). The IOP, PD, heart rate, and mean arterial pressure were measured prior to baseline and 5, 10, and 20 min after drug administration. Data were analysed using one- and two-way repeated measures ANOVA or their non-parametric equivalents (P < 0.05). No significant differences in IOP within or between groups were recorded. In the MV-group, PD remained unchanged compared to baseline. In the M-group, PD significantly (P = 0.007, P < 0.001, P < 0.001) decreased compared to baseline at all observation times. PD was significantly (P = 0.010, P < 0.001, P < 0.001) smaller in the M-group at all observation times compared to the MV-group. Vatinoxan co-administered with medetomidine, as well as medetomidine alone, did not significantly influence IOP. Vatinoxan with medetomidine did not affect PD, while medetomidine alone significantly reduced it.

Keywords: alpha-2 adrenoreceptor agonist; alpha-2 adrenoreceptor antagonist; MK-467; L-659,066; pupil size

Received: June 30, 2025; Revised: September 2, 2025; Accepted: September 3, 2025; Prepublished online: December 19, 2025; Published: December 31, 2025  Show citation

ACS AIP APA ASA Harvard Chicago Chicago Notes IEEE ISO690 MLA NLM Turabian Vancouver
Rauser P, Mrazova M, Sabatova A, Jiraskova K. Effect of vatinoxan co-administered with medetomidine on intraocular pressure and pupil diameter in healthy dogs. Vet Med - Czech. 2025;70(12):427-431. doi: 10.17221/47/2025-VETMED.
Share...
Download citation
  • BibTeX (.bib)
  • Bookends (.ris)
  • EasyBib (.ris)
  • EndNote (.enw)
  • EndNote 8 (.xml)
  • ISI WoS (.isi)
  • Medlars (.medlars)
  • Mendeley (.ris)
  • MODS (.xml)
  • Papers (.ris)
  • RefWorks (.txt)
  • RefManager (.ris)
  • RIS (.ris)
  • MS Word (.xml)
  • Zotero (.ris)
    • Open full article

    References

    1. Aghababaei A, Ronagh A, Mosallanejad B, Baniadam A. Effects of medetomidine, dexmedetomidine and their combination with acepromazine on the intraocular pressure IOP, tear secretion and pupil diameter in dogs. Vet Med Sci. 2021 Mar 10;7(4):1090-5. Go to original source... Go to PubMed...
    2. Almeida DE, Rezende ML, Nunes N, Laus JL. Evaluation of intraocular pressure in association with cardiovascular parameters in normocapnic dogs anesthetized with sevoflurane and desflurane. Vet Ophthalmol. 2004 Jul-Aug;7(4):265-9. Go to original source... Go to PubMed...
    3. Bertoni P. Valutazione comparativa di pressione intraoculare e produzione lacrimale in cani sedati con Zenalpha or medetomidina [Comparative evaluation of intraocular pressure and tear production in dogs sedated with Zenalpha or medetomidine]. Thesis. Padua (Italy): University of Padua; 2024. 145 p.
    4. Gelatt KN, Brooks DE. The canine glaucomas. In: Gelatt KN, editor. Veterinary ophthalmology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999. p. 701-54.
    5. Honkavaara JM, Raekallio MR, Syrja PM, Pypendop BH, Knych HK, Kallio-Kujala IJ, Vainio OM. Concentrations of medetomidine enantiomers and vatinoxan, an alpha2-adrenoceptor antagonist, in plasma and central nervous tissue after intravenous coadministration in dogs. Vet Anaesth Analg. 2020 Jan;47(1):47-52. Go to original source... Go to PubMed...
    6. Johnstone M, Xin Ch, Tan J, Martin E, Wen J, Wang RK. Aqueous outflow regulation - 21st century concepts. Prog Retin Eye Res. 2021 Jul;83:100917. Go to original source... Go to PubMed...
    7. Kanda T, Iguchi A, Yoshioka Ch, Nomura H, Higashi K, Kaya M, Yamamoto R, Kuramoto T, Furukawa T. Effects of medetomidine and xylazine on intraocular pressure and pupil size in healthy Beagle dogs. Vet Anaesth Analg. 2015 Nov;42(6):623-8. Go to original source... Go to PubMed...
    8. Mrazova M, Rauser P, Burova J, Georgiou M, Fichtel T. Influence of medetomidine, acepromazine, fentanyl or butorphanol on intraocular pressure and pupil size in healthy dogs. Vet Med-Czech. 2018 Sep;63(9):413-9. Go to original source...
    9. Murrell JC, Hellebrekers LJ. Medetomidine and dexmedetomidine: A review of cardiovascular effects and antinociceptive properties in the dog. Vet Anaesth Analg. 2005 May;32(3):117-27. Go to original source... Go to PubMed...
    10. Randall HS. Comparative neuro-ophthalmology. In: Gelatt KN, editor. Veterinary ophthalmology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999. p. 1307-400.
    11. Renwick P. Glaucoma. In: Petersen-Jones S, Crispin S, editors. BSAVA manual of small animal ophthalmology. 2nd ed. Gloucester, UK: BSAVA; 2002. p. 185-203.
    12. Rolfe NG, Kerr CL, McDonell WN. Cardiopulmonary and sedative effects of the peripheral alpha2-adrenoceptor antagonist MK 0467 administered intravenously or intramuscularly concurrently with medetomidine in dogs. Am J Vet Res. 2012 May;73(5):587-94. Go to original source... Go to PubMed...
    13. Verbruggen AM, Akkerdaas LC, Hellebrekers LJ, Stades FC. The effect of intravenous medetomidine on pupil size and intraocular pressure in normotensive dogs. Vet Q. 2000 Jul;22(3):179-80. Go to original source... Go to PubMed...
    14. Wallin-Hakanson N, Wallin-Hakanson B. The effects of topical tropicamide and systemic medetomidine, followed by atipamezole reversal, on pupil size and intraocular pressure in normal dogs. Vet Ophthalmol. 2001 Mar;4(1):3-6. Go to original source... Go to PubMed...
    15. Wrezesniewska K, Madany J, Winiarczyk D. Comparison of intraocular pressure measurement with Schiotz Tonometer and Tono-Pen Vet Tonometer in healthy dogs. J Vet Res. 2018 Oct 24;62(2):243-7. Go to original source... Go to PubMed...

    This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY NC 4.0), which permits non-comercial use, distribution, and reproduction in any medium, provided the original publication is properly cited. No use, distribution or reproduction is permitted which does not comply with these terms.


    Return to the content