A Review on the Current Use of Alpha(2) Agonists in Small Ruminants

作者：Shah, Zahir; Ding, Ming-Xing^*; Hu, Man-Li

来源：Kafkas Universitesi Veteriner Fakultesi Dergisi, 2014, 20(4): 633-639.

DOI：10.9775/kvfd.2013.10541

• Alpha(2) adrenergic agonists
• Alpha(2) receptor
• Sedation
• Analgesia
• Premedications
• Anesthesia
• Ruminant

In recent years, alpha(2) agonists are the most widely used as sedative and analgesic drugs in veterinary medicine because of several useful properties like fast onset, reversibility and analgesia. Alpha(2) agonists produce different actions by binding to their corresponding receptor subtypes located on various parts of the central nervous system. Ruminants are especially sensitive to alpha(2) agonists due to the distribution of the specific alpha(2) adrenoceptor subtypes, compared with other species. In ruminants, alpha(2) agonists are generally used as sedatives and analgesics for restraint, clinical diagnosis, and minor surgeries. Clinical experiments indicated that analgesia does not exist throughout the period of sedation, so these agents alone are not sufficient for painful or major surgical procedure. Epidural administration of alpha(2) agonists produced potent analgesia with minimal sedative or cardiovascular effects, and considered one of the most reliable techniques in ruminant. Alpha(2) agonists also used as a preanesthetic medication and have been obviously anesthetic sparing effects. They causes some unwanted effects, such as excessive saliva, bradycardia, depressed respiratory rate, decreased rectal temperature, hyperglycemia, uterine contractions and decreased ruminal and intestinal motility. These side effects are influenced by the doses and administration routes of alpha(2) agonists, and their selectivity to alpha(2) adrenoceptor subtypes. Attentions should be taken to avoid the use of these agents in sick patients, while careful monitoring of the patient condition is always mandatory after receiving these agents. Fortunately, the availability of specific antagonists assures the uses of alpha(2) agonists in ruminants. For the safety, an appropriate low dose of alpha(2) agonists is always recommended in ruminants.

• 出版日期2014-8
• 单位华中农业大学