The sedative effect of intranasal administration of medetomidine using a mucosal atomization device in Japanese White rabbits

• Published in: Journal of Veterinary Medical Science Vol. 85; no. 4; pp. 22-0484 - 478
• Main Authors: WEI, Yixian, CHEN, I-Ying, TAMOGI, Haruka, SUGITA, Chihiro, DAIMARUYA, Nozomi, HIROKAWA, Taku, KATO, Keiko, ITAMI, Takaharu, SANO, Tadashi, YAMASHITA, Kazuto
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 2023; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Administration, Intranasal - veterinary; Aerosols - administration & dosage; Aerosols - pharmacology; Animals; Blood pressure; Carbon dioxide; Female; Heart Rate - drug effects; Hypnotics and Sedatives - administration & dosage; Hypnotics and Sedatives - pharmacology; Intranasal administration; intranasal atomization; medetomidine; Medetomidine - administration & dosage; Medetomidine - pharmacology; Mucosa; mucosal atomization device; rabbit; Rabbits; Respiration; Righting reflex; Surgery; intranasal atomization; medetomidine; mucosal atomization device; rabbit
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.22-0484

To prevent aspiration in Japanese White (JW) rabbits, the maximum single volume of medetomidine administered intranasally is 0.3 mL per nostril using a mucosal atomization device (MAD). This study aimed to examine the sedative effect of intranasal administration of medetomidine using MAD in eight healthy female JW rabbits. Each rabbit received intranasal atomization (INA) of saline (Control treatment) along with three doses of 1 mg/mL medetomidine (0.3 mL to one nostril [MED0.3 treatment]; 0.3 mL each to both nostrils [MED0.6 treatment]; 0.3 mL twice to both nostrils [MED1.2 treatment]), with a washout period of at least 7 days between treatments. The actual doses of medetomidine were 82 (75–84) μg/kg (median [interquartile range]), 163 (156–168) μg/kg, and 323 (295–343) μg/kg for the MED0.3, MED0.6, and MED1.2 treatments, respectively. A medetomidine-dose dependent sedative effect was detected, and the loss of righting reflex (LRR) was achieved in one rabbit at 18 min, seven rabbits at 11 (9–18) min, and eight rabbits at 7 (4–18) min after the MED0.3, MED0.6, and MED1.2 treatments, respectively. The LRR was maintained for 63 (29–71) min and 83 (68–101) min after the MED0.6 and MED1.2 treatments, respectively. Additionally, the INA of medetomidine produced a significant dose-dependent cardiorespiratory depression including a decrease in pulse rate, respiratory rate, percutaneous oxygen saturation, and arterial partial pressure of oxygen, and an increase in arterial partial pressure of carbon dioxide in the rabbits.