Patients with chronic congestive heart failure (CHF) are known to have elevated plasma concentrations of norepinephrine. Although this elevation of catecholamines in plasma may facilitate myocardial contractility, it may also be toxic to the myocardium in the long term. The alpha2 adrenoreceptor located on noradrenergic nerve terminals regulates neuronal norepinephrine release by feedback inhib...

1. The interaction between prazosin and clonidine was studied in anaesthetized rats, pithed rats and in anaesthetized cats. 2. Prazosin diminished the clonidine-induced hypotensive effect in anaesthetized rats, probably via an antagonism at the level of central alpha-adrenoreceptors. 3. In pithed rats, stimulation of the Nervi accelerantes caused tachycardia, which was diminished considerably b...

We have studied the use of clonidine combined with low doses of sufentanil and bupivacaine in 45 parturients requiring extradural analgesia for the first stage of labour, in a double-blind, randomized study. We gave 0.0625% bupivacaine 10 ml containing 1:200,000 adrenaline and sufentanil 10 micrograms (1 ml) to which was added 0.9% saline, or clonidine 100 or 150 micrograms (1 ml). We compared ...

This is a prospective randomized double-blind trial conducted to determine whether preoperative orally administered clonidine causes or potentiates postoperative vomiting in 140 children (3-12 yr) undergoing strabismus surgery. They were all inpatients and classified randomly into four groups (n = 35 each); placebo (control), diazepam 0.4 mg.kg-1, clonidine 2 micrograms.kg-1, and clonidine 4 mi...

OBJECTIVE Clonidine, an alpha-2 adrenergic agonist, increases the quality of perioperative sedation and analgesia with a few side effects. This study was designed to assess the effect of clonidine premedication on the anesthesics used for elective below knee surgeries in opium abusers and non-abusers. MATERIALS AND METHODS In a randomized clinical trial, 160 patients were selected and assigne...

BACKGROUND Clonidine has been added to local anesthetic regimens for various peripheral nerve blocks, resulting in prolonged anesthesia and analgesia. The authors postulated that using clonidine as a component of intravenous regional anesthesia (IVRA) would enhance postoperative analgesia. METHODS Forty-five patients undergoing ambulatory hand surgery received IVRA with lidocaine, 0.5%, and w...

BACKGROUND Inhibition of cardiac sympathetic tone represents an important strategy for treatment of cardiovascular disease, including arrhythmia, coronary heart disease, and chronic heart failure. Activation of presynaptic alpha2-adrenoceptors is the most widely accepted mechanism of action of the antisympathetic drug clonidine; however, other target proteins have been postulated to contribute ...

Clonidine, a noradrenergic alpha-2 agonist, can initiate locomotion early after spinalization in cats. Because this effect lasts 4-6 h, we have injected clonidine daily, intraperitoneally or intrathecally, and intensively trained five spinal cats to perform hindlimb walking on a treadmill starting at day 3 and continuing until 10 days posttransection. Each day, clonidine was injected to induce ...