Clonidine is reported to inhibit the az-adrenoceptor mediated pinnal reflex in mice (3). Clonidine produces its effect by acting as an oc2-adrenergic autoreceptor agonist (1). As such, clonidine is also agonist for presynaptic histamine Hz-receptors (8). To test whether the clonidine-induced inhibition of the pinnal reflex is mediated through adrenergic and/or histaminergic system, the interact...

BACKGROUND This systematic review and meta-analysis investigates the efficacy and safety of clonidine as a sedative in critically ill patients requiring invasive mechanical ventilation. METHODS We performed a comprehensive search of MEDLINE, EMBASE, CINAHL and the Cochrane trial registry. We identified RCTs that compared clonidine to any non-clonidine regimen in critically ill patients, exclu...

The effect of short-term diuretic treatment on the action of clonidine was evaluated in eight subjects with mild, uncomplicated hypertension. A single oral dose of clonidine (0.3 mg) was given before and after 1 week of therapy with hydrochlorothiazide, 50 mg, and amiloride, 5 mg, taken daily. Changes in mean arterial pressure, heart rate, plasma norepinephrine and epinephrine levels, and plasm...

Clonidine in paediatric anaesthesia: Pharmacokinetic and pharmacodynamic aspects. Henrik TG Bergendahl. Stockholm 2002. Clonidine is a mixed alpha-2/alpha-1 adrenoceptor agonist. It reduces sympathetic and increases parasympathetic tone which results in a lowering of the baseline blood pressure and heart rate. Descending postjunctional noradrenergic antinociceptive pathways originating in the b...

crossover study, clonidine, 0.3 mg/day orally for 3 days, significantly reduced systolic and diastolic blood pressure and heart rate, whereas placebo was ineffective. Naloxone, 0.4 mg given intravenously on the third day of clonidine treatment, caused a rapid increase in blood pressure and heart rate in 14 patients (reacting group), but was ineffective in the remaining 13 patients (nonreacting ...

Clonidine failed to reduce the blood pressures of two patients with essential hypertension. On was given 5-4 mg/day and the other 6 mg/day, and their respective peak plasma clonidine concentrations were 26-2 ng/ml and 14-4 ng/ml. Several months after the end of clonidine treatment a single oral dose of 0-3 mg of clonidine produced maximum falls in blood pressure of 30/22 mm Hg and 88/41 mm Hg w...

conclusions premedication with clonidine to decrease intraoperative blood loss can be more effective in patients with opium addiction than the ones without addiction. results intraoperative blood loss in clonidine recipient groups, patients with and without addiction, was less than that of the placebos (both p values < 0.01) and the difference magnitude was higher in patients with opium addicti...

BACKGROUND Perioperative myocardial ischemia occurs in 20-40% of patients at risk for cardiac morbidity and is associated with a ninefold increase in risk of cardiac morbidity. METHODS In a prospective, double-blinded, clinical trial, we studied 190 patients with or at risk for coronary artery disease in two study groups with a 2:1 ratio (clonidine, n = 125 vs. placebo, n = 65) to test the hy...

PURPOSE We investigated whether low-dosed oral clonidine premedication before elective intraocular surgery in retrobulbar anesthesia is effective in terms of anxiolysis, sedation, stable hemodynamics, lower intraocular pressure and perioperative endocrine stress response. METHODS In a prospective, randomised, double-blind study, 44 patients scheduled for elective intraocular surgery received ...

BACKGROUND Clonidine effectively decreases perioperative mortality by reducing sympathetic tone. However, application of clonidine might also restrict anaemia tolerance due to impairment of compensatory mechanisms. Therefore, the influence of clonidine induced, short-term sympathicolysis on anaemia tolerance was assessed in anaesthetized pigs. We measured the effect of clonidine on anaemia tole...