Alpha-Adrenergic
Receptor Agonist Activity

Commentary by
Dr. W David Watkins,
AnesthesiaWeb
Advisory Board

The application of drugs with alpha-adrenergic receptor agonist activity, e.g., clonidine, has been long promoted in various clinical contexts--the treatment of pain, and as adjunct therapy in regional and general anesthesia. Although considerable and diverse laboratory and clinical research has been devoted to this topic, only recently are reports beginning to appear in the literature, describing the systematic application of this category of drugs in the clinical practice setting. Two such articles are recommended for review:

Small, oral dose of clonidine reduces the incidence of intraoperative myocardial ischemia in patients having vascular surgery.
Stuhmeier K-D, Mainzer B, Cierpka J, Sandmann W, Tarnow J Anesthesiology 1996; 85:706-712
[ read the abstract ]

Alpha-2-Adrenergic agonists for regional anesthesia.
Eisenach JC, De Kock M, Klimscha W, Anesthesiology 1996; 85:655-674
[ No abstract published ]


The first article by Eisenach, et al, is an excellent clinical review of the use of clonidine in regional anesthesia over the time frame of 1984-95. They systematically review the pharmacologic principles of related to this drug class, followed by the specific applications of clonidine administration epidurally, intrathecally and peripherally. The article summarizes the doses, predominant effects and safety considerations in a manner of use for the clinician. An extensive bibliography is helpful for the reader interested in details arising from this review.

The second recommended article is a recent clinical investigation focusing on a specific application of clonidine in patients undergoing vascular surgery--a population particularly susceptible to significant perioperative myocardial ischemic episodes. In their study consisting of 297 patients undergoing elective vascular procedures, they found that pretreatment with a small oral dose of clonidine was associated with a reduction in the incidence of perioperative myocardial ischemic episodes from 39% to 24%. Of particular interest, nonfatal myocardial infarction occurred in 4 control (untreated) patients while in none of the clonidine-treatment group. If the results of this study withstand test of larger numbers of patients and practitioners, a simple, benign treatment of this kind may pay substantial benefits in the quality of care and its associated costs.


Also see...


Back to the Literature Review front page