alpha-2 and imidazoline receptor agonists. Their pharmacology and therapeutic role

Anaesthesia. 1999 Feb;54(2):146-65. doi: 10.1046/j.1365-2044.1999.00659.x.


Clonidine has proved to be a clinically useful adjunct in clinical anaesthetic practice as well as in chronic pain therapy because it has both anaesthetic and analgesic-sparing activity. The more selective alpha-2 adrenoceptor agonists, dexmedetomidine and mivazerol, may also have a role in providing haemodynamic stability in patients who are at risk of peri-operative ischaemia. The side-effects of hypotension and bradycardia have limited the routine use of alpha-2 adrenoceptor agonists. Investigations into the molecular pharmacology of alpha-2 adrenoceptors have elucidated their role in the control of wakefulness, blood pressure and antinociception. We discuss the pharmacology of alpha-2 adrenoceptors and their therapeutic role in this review. The alpha-2 adrenoceptor agonists are agonists at imidazoline receptors which are involved in central blood pressure control. Selective imidazoline agonists are now available for clinical use as antihypertensive agents and their pharmacology is discussed.

Publication types

  • Review

MeSH terms

  • Adjuvants, Anesthesia
  • Adrenergic alpha-2 Receptor Agonists*
  • Adrenergic alpha-Agonists / pharmacokinetics
  • Adrenergic alpha-Agonists / pharmacology*
  • Analgesia / methods
  • Anesthesia / methods*
  • Animals
  • Hemodynamics / drug effects
  • Humans
  • Imidazoles / pharmacokinetics*
  • Imidazoline Receptors
  • Receptors, Drug / agonists*


  • Adjuvants, Anesthesia
  • Adrenergic alpha-2 Receptor Agonists
  • Adrenergic alpha-Agonists
  • Imidazoles
  • Imidazoline Receptors
  • Receptors, Drug