I.v. clonidine: does it work as a hypotensive agent with inhalation anaesthesia?

Abstract

In a double-blind, randomized, placebo-controlled study, 41 patients received clonidine 3 micrograms kg-1 or placebo at induction of isoflurane and nitrous oxide in oxygen anaesthesia. Metoprolol was also given to achieve a systolic arterial pressure of 80 mm Hg. Requirements for metoprolol were significantly less in the clonidine group (P < 0.00035), with no significant difference in mean arterial pressures over time. It would appear that clonidine is an i.v. hypotensive agent worthy of consideration, but data during the recovery period are required to comment further on the safety of this technique.

Effect of Clonidine Premedication on Blood Loss in Spine Surgery

“…Clonidine was shown to reduce bleeding during middle ear surgery under isoflurane anesthesia in 2 studies. It also reduced the doses of isoflurane and fentanyl in both studies (13)(14)(15)(16). In our study, clonidine significantly reduced the dose of remifentanil needed to maintain the same levels of hypotension as the control group.…”

“…The preferred technique is a combination of remifentanil with propofol or an inhalation agent (isoflurane, desflurane, or sevoflurane) (7)(8)(9)(10)(11). Alpha-2 adrenergic agonists (clonidine and dexmedetomidine) have been used successfully as adjuvants, oral premedication, and intravenous infusion during anesthesia to induce controlled hypotension (12)(13)(14)(15)(16)(17)(18)(19)(20). Clonidine is an alpha-2 adrenergic agonist, which has been used as a centrally acting antihypertensive drug.…”

Evaluation of Clinical Efficacy of Clonidine as an Adjuvant to General Anaesthesia in Elective Faciomaxillary and Aesthetic Face Surgery - The Prospective Randomized Single Blind Controlled Study

“…1, 2, 3 and graph 3 to 7 compared with baseline measurement, there was significantly less increase in heart rate and blood pressure in group II compared to group I. The same hypotensive effect of clonidine is elicited by Pandazi et al; Lee J et al; Gupta K et al; Singh S et al; Hackman et al; Farah et al; Sung C S et al [3], [19], [13], [6], [7], [5], [18] Clonidine for premedication has been used by other authors who have documented maintenance of stable haemodynamics during intubation, extubation, intraoperative and postoperative period. Clonidine as an oral, i.v.…”

Comparative Evaluation of Oral Clonidine and Oral Atenolol as Premedication in Functional Endoscopic Sinus Surgery (FESS) Under General Anaesthesia

“…Clonidine has gained popularity as an adjuvant drug in anesthesia for its sedative and analgesic effects [12] , as well as for its favorable effects on the hemodynamic profile of patients [13] . It has been used to reduce intraoperative bleeding in major abdominal and orthopedic surgeries through its hypotensive effects [14,15] . Clonidine as an alpha 2 agonist constricts peripheral blood vessels [16] , and has been suggested to reduce nasal mucous blood flow in animal models [17] .…”