[Clonidine and anesthesia]

The alpha2-adrenoceptor agonists have several beneficial actions during the perioperative period. They exert a central sympatholytic action, improving haemodynamic stability in response to endotracheal intubation and surgical stress, reducing the anesthetic and opioid requirements and causing sedation, anxiolysis and analgesia. Furthermore, alpha2-adrenoceptor agonists may offer benefits in the prophylaxis and treatment of perioperative myocardial ischaemia. Recent alpha2-adrenoceptor agonists with short duration of action (dexmedetomidine and mivazerol) are adapted for the administration to patients at high risk for coronary artery disease during surgery. The alpha2-adrenoceptor agonists have an analgesic action at several sites of the peripheral and central nervous system as well as the prolongation of epidurally or intrathecally administered local anesthetics and opioids.