Search Results
Results 251 - 300 of 1019
< 1 2 3 4 5 6 7 8 9 10 11 >
Backo Angel L - - 2002
To report a case of possible clonidine-induced hypertension (by Naranjo score) in a patient with a C4 spinal lesion. Clonidine is a medication long used to treat hypertension, and it is still used in the treatment of refractory hypertension. Although effective, clonidine use is hindered by adverse effects and its ...
Stensløkken K-O - - 2002
Little is known of the cardiovascular functions of prostaglandins in non-mammalian vertebrates. There are indications that prostaglandins may have a function in haemostasis by constricting blood vessels in filament arteries in the fish gill after injury. Our aim was to examine the cardiovascular effect of the prostaglandins F(2 alpha) (PGF(2 ...
Stine Susan M - - 2002
BACKGROUND: Alteration in noradrenergic regulation as well as alteration in the hypothalamic-pituitary-adrenal (HPA) axis have been associated with opioid dependence and acute abstinence symptoms. METHODS: This double-blind, placebo-controlled study evaluated subjective, physiologic, and biochemical responses to yohimbine (.4 mg/kg, IV) in eight patients receiving methadone and compared results to those ...
Victor Ronald G - - 2002
PURPOSE: Clonidine, an alpha(2)-adrenergic agonist, raises blood pressure in patients with autonomic failure, in whom failure of reflex neurogenic venoconstriction leads to severe orthostatic hypotension. Because animal studies suggest that postjunctional alpha(2)-adrenoreceptors are located mainly on venous capacitance rather than arterial resistance vessels, we tested the hypothesis that venoconstriction is ...
Prisant L Michael - - 2002
The clonidine transdermal therapeutic system is being used as a therapy for blood pressure treatment. Systemic side effects seem to be fewer than with oral clonidine. However, localized skin reactions occur frequently and the incidence increases with the dose and duration of use. Common signs include erythema, scaling, vesiculation, excoriation, ...
Zalunardo Marco P - - 2002
Although the mechanism of tourniquet-induced hypertension is still unclear, plasma norepinephrine concentrations continuously increase in parallel to arterial blood pressure during tourniquet inflation. Clonidine attenuates hyperadrenergic and hyperdynamic responses. We investigated the effects of clonidine on prolonged tourniquet inflation. Twenty-nine patients scheduled for elective orthopedic surgery were randomly assigned to ...
Brune Michael E - - 2002
Fiduxosin is an alpha(1)-adrenoceptor antagonist with higher affinity for alpha(1A)-adrenoceptors and for alpha(1D)-adrenoceptors than for alpha(1B)-adrenoceptors. Our hypothesis is that such a compound with higher affinity for subtypes implicated in the control of lower urinary tract function and lower affinity for a subtype implicated in the control of arterial pressure ...
Schindler C W - - 2002
Conscious squirrel monkeys were treated i.v. with cocaine and various dopamine agonist drugs. Cocaine produced a dose-dependent increase in blood pressure, heart rate, and the rate-pressure product (RPP). The dopamine D1 receptor agonist (+/-)-6-chloro-3-allyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide (SKF 82958) produced effects comparable to cocaine. The D1 agonist (+/-)-6-chloro-7, 8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide (SKF 81297) ...
Michaluk Jerzy - - 2002
It is well recognized that 1,2,3,4-tetrahydroisoquinoline (TIQ) is a substance capable of inducing in animals a syndrome, regarded as an animal model of Parkinson's disease. This study was designed to evaluate the effect of the endogenous neurotoxin TIQ on the brain noradrenaline (NA) metabolism in mice and on an arterial ...
Brown J - - 2001
A case of ventricular tachycardia which reverted with intravenous methoxamine is presented. The methoxamine was used to increase blood pressure during anaesthesia for direct current cardioversion. While alpha adrenergic agonists have been used previously to increase vagal tone via a baroreceptor mechanism to revert supraventricular tachycardias, this is the first ...
Gavras I - - 2001
This is a brief overview of experimental and clinical studies exploring the hemodynamic functions of the alpha2A and alpha2B adrenergic receptor (AR) subtypes in animals submitted to genetic manipulations or gene treatment, as well as the clinical effects of central sympathetic suppression with the alpha2-AR agonist clonidine in patients with ...
Dobrucki L W - - 2001
Background- Clonidine has an antihypertensive effect by its action in the brain and, because we observed that the tonic production of nitric oxide (NO) in the brain is required to maintain blood pressure at its low, normotensive level, the current study was designed to determine whether the hypotensive action of ...
Szeto H H - - 2001
IV administration of mu-opioid peptide agonists (DAMGO, DALDA, and [Dmt(1)]DALDA) results in a transient, naloxone-sensitive, increase in blood pressure in awake sheep. Despite significant differences in pharmacokinetics, these blood pressure responses all last < 15 min. The lack of correlation between half-life and duration of action suggested rapid desensitization. When ...
Laisalmi M - - 2001
BACKGROUND: Carbon dioxide pneumoperitoneum causes a hemodynamic stress response and decreases urine output because of an activated renin-angiotensin-aldosterone system (RAAS). Clonidine is a potent antihypertensive drug that suppresses RAAS. METHODS: The effects of clonidine 4.5 mg/kg or saline on hemodynamics, neuroendocrine response, and renal parameters were compared in 30 healthy ...
Grassi G - - 2001
Congestive heart failure is characterized by a sympathetic activation that is coupled with a baroreflex impairment. Whether these alterations are affected by clonidine is unknown. In 26 normotensive patients age 58.0+/-1.1 years (mean+/-SEM) affected by congestive heart failure (New York Heart Association functional class II or III) and treated with ...
Jellish W S - - 2001
This study was designed to determine if oral clonidine or lidocaine, injected into the scalp before head-holder (H-H) insertion, would attenuate the hemodynamic effects associated with intubation and H-H placement. Thirty-four patients undergoing skull base procedures were randomized to four groups. Group 1 received clonidine 5 mcg/kg po before surgery ...
Talke P O - - 2001
We evaluated the vasomotor effects of clonidine in awake subjects with an intact central cardiovascular regulatory system. To determine the lower limit of the vasoconstrictive effect of clonidine in awake volunteers, we blocked sympathetic innervation to the left arm by anesthetizing the brachial plexus. We then measured arterial blood pressure ...
Kimura Y - - 2001
BACKGROUND AND OBJECTIVES: The aim of this study is to examine the duration and magnitude of vasodilative effect induced by sympathetic block with the addition of clonidine to mepivacaine. METHODS: We measured mean arterial pressure (MAP), heart rate (HR), and right and left brachial artery blood flow (BABF) before and ...
Rives J E - - 2001
The effect of adrenergic agents on the central control of breathing in the cane toad, Bufo marinus, was tested by applying adrenergic agents to the ventral medullary surface of decerebrate adult toads. Toads were unidirectionally ventilated while recording lung, buccal, and artery blood pressures (BPI), as well as heart rate ...
Doggrell S A - - 2001
Initially it was considered that moxonidine, like clonidine, acted at central (2)-adrenoceptors to reduce blood pressure. With the characterisation of imidazoline binding sites distinct from (2)-adrenoceptors, the consensus became that moxonidine was acting predominantly at imidazoline I(1) receptors in the rostral ventrolateral medulla to lower blood pressure. Moxonidine acts at ...
Boussofara M - - 2001
BACKGROUND AND OBJECTIVE: This study compares the effect of oral clonidine vs. hydroxyzine on the haemodynamic and catecholamine responses to microlaryngoscopy. METHODS: Thirty-five ASA II-III patients were included in this double-blind randomized trial. The patients received either hydroxyzine 1 mg kg-1 (n = 18) or clonidine 3 micrograms kg-1 (n ...
Alhashemi J A - - 2001
A 67-yr-old female received hypertensive, hypervolaemic treatment for cerebral vasospasm after severe subarachnoid haemorrhage. After 3 days of continuous vasopressor infusion and despite adequate hydration and normal cardiac function, the phenylephrine dose had to be increased to obtain the same systolic blood pressure. This tachyphylaxis to phenylephrine infusion was probably ...
Gertler R - - 2001
Since the first report of clonidine, an alpha2-adrenoceptor agonist, the indications for this class of drugs have continued to expand. In December 1999, dexmedetomidine was approved as the most recent agent in this group and was introduced into clinical practice as a short-term sedative (<24 hours). Alpha2-adrenoceptor agonists have several ...
Maruyama K - - 2000
Alpha-2 adrenergic agonists including clonidine decrease cerebral blood flow. The specific actions of clonidine on cerebrospinal fluid (CSF) pressure in humans remain to be elucidated. We evaluated the effect of oral clonidine premedication on lumbar CSF pressure in patients without intracranial disease. Seventy-four patients undergoing subarachnoidal block were divided randomly ...
O'Halloran K D - - 2000
We examined the effects of the alpha(2)-adrenoceptor (alpha(2)-AR) agonist clonidine on pressure-flow relationships in the upper airway. Inspired and expired airflows, subglottic tracheal pressure (PTR), mask pressure and middle pharyngeal constrictor (MPC) and diaphragm electromyogram (EMG) activities were recorded in awake standing goats. Clonidine-induced central apneas were always associated with ...
Tranchant C - - 2000
Clonidine, a centrally active alpha 2-adrenoreceptor agonist used to lower blood pressure, has been proposed to differentiate central from peripheral autonomic deficits and multiple system atrophy (MSA) from untreated idiopathic Parkinson's disease (IPD). A lack of growth hormone (GH) increase after clonidine infusion is found in patients with MSA, but ...
Sattar M A - - 2000
1. This study compared the effect of a non-peptide angiotensin II receptor antagonist and a series of clonidine analogues on blood pressure and renal function in a two-kidney two-clip Goldblatt rat model of hypertension subjected to 2 weeks of dietary sodium deprivation. 2. Animals received either vehicle, the angiotensin II ...
Prause A - - 2000
OBJECTIVE: Assessment of respiratory depression caused by long-term sedation with sufentanil, midazolam and clonidine. DESIGN: Retrospective assessment using data from a patient data management system. SETTING: University hospital anaesthesiological ICU. PATIENTS: Three hundred ninety-five surgical and trauma patients with an ICU stay of more than 48 h. INTERVENTION: None. MEASUREMENTS ...
Crippa G - - 2000
A 36-year-old woman (gravida 2, para 2) delivered a healthy child by cesarean section at the 37th week of an unremarkable gestation. Blood pressure remained within normal range throughout the pregnancy, surgery, and for the 9 following days. On day 10, about 36 hours after the initiation of oral methergoline ...
Talke P O - - 2000
Large concentrations of alpha(2) agonists cause vasoconstriction. However, the threshold of the vasoconstrictive effect in humans is not known. We studied seven volunteers to determine the lower limit of the vasoconstrictive effect of clonidine. Subjects were studied while they were awake, and they were anesthetized with propofol/alfentanil/N(2)O. Arterial blood pressure ...
Matot I - - 2000
The usual hemodynamic response to laryngoscopy and bronchoscopy is an increase in heart rate and arterial blood pressure. Previous work has reported that 10%-18% of the patients develop ischemic ST segment changes during the procedure. Therefore, we performed a prospective, randomized, double-blinded study in 36 patients scheduled for elective microlaryngeal ...
Blake D W - - 2000
1. Effects of the alpha2-adrenoceptor agonist dexmedetomidine on vasoconstrictor and heart rate (HR) responses to acute central hypovolaemia were studied in eight chronically instrumented rabbits. We compared intravenous (i.v.) and fourth ventricular (V4) dexmedetomidine (0.1-10 microg/kg) and the reversal of effects by the alpha2-adrenoceptor antagonist idazoxan and the opioid agonist ...
Quevedo M - - 2000
Fenoldopam (FD) and levodopa (LD) injected intravenously in rats in a noncumulative schedule induced dose-dependent reductions in mean arterial blood pressure. The doses that induced a 50% reduction in the initial control mean arterial pressure (referred as ED50) were calculated by linear regression analysis of the corresponding parallel dose-response curves ...
Gregorakos L - - 2000
The aim of this study was to identify the effectiveness of clonidine in the recovery of patients with neuroleptic malignant syndrome and autonomic dysfunction, including blood pressure lability. Nine patients with neuroleptic malignant syndrome and autonomic dysfunction were treated with clonidine in the intensive care unit, according to a protocol, ...
van Zwieten P. A. - - 2000
Classic centrally acting drugs such as clonidine and alpha-methyldopa induce peripheral sympatho-inhibition via the stimulation of alpha(2)-adrenoceptors in the brainstem. From a haemodynamic point of view this appears to be a useful mechanism to lower elevated blood pressure in hypertensives. Although not known in full detail, a complex relationship exists ...
Liechti M E - - 2000
3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy") releases serotonin and dopamine. The role for dopamine in mediating the effects of MDMA has not yet been examined in humans. We investigated the effect of pretreatment with the dopamine D(2) antagonist haloperidol (1.4 mg i.v.) on psychological and physiological responses to MDMA (1.5 mg/kg p.o.) in ...
Weindler J - - 2000
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 either 0.15 mg ...
Ferrier G M - - 2000
Aseptic loosening and osteolysis around prosthetic joints are the principal causes of failure and consequent revision. During this process activated macrophages produce cytokines which are thought to promote osteolysis by osteoclasts. Changes in pressure within the space around implants have been proposed as a cause of loosening and osteolysis. We ...
Gajjar D - - 2000
The pathophysiological factors of neurogenic or sympathetically mediated essential hypertension are unknown. Neurons close to the surface of the ventrolateral medulla (specifically, in the retro-olivary sulcus [ROS]) are integrally involved in the control of blood pressure by means of efferent connections to presympathetic neurons in the spinal cord. It is ...
Poisson D - - 2000
Numerous studies have addressed the antihypertensive properties of I(1)-imidazoline receptor agonists such as moxonidine, but very few authors examined their cardiac antiarrhythmic potency. Due to the important role of the sympathetic nervous system in the genesis of neurogenic cardiac arrhythmias, we investigated the antiarrhythmic effects of moxonidine and compared them ...
Dodick D W - - 2000
The clinical syndrome of hypertension, headache, palpitation, diaphoresis, flushing, and emotional lability is classically associated with pheochromocytoma. Two patients are presented with this constellation of symptoms in whom investigations for pheochromocytoma were unrevealing. Headache was the presenting and most prominent complaint, with daily episodes of short-lasting, intermittent, and paroxysmal attacks. ...
Phillips M A - - 2000
RATIONALE: Spontaneous fluctuations in the size of the pupil in darkness are a recognized index of sleepiness, and these fluctuations can be quantitatively measured using the pupillographic sleepiness test (PST). The central noradrenergic system is believed to play a role in the maintenance of alertness, and there is evidence that ...
Matot I - - 2000
The usual haemodynamic response to fibreoptic bronchoscopy is an increase in heart rate and blood pressure. We therefore compared, in a prospective, randomised, double-blind study, the effect of two doses of oral clonidine premedication (150 microg or 300 microg) with placebo (control group) on the haemodynamic alterations in 62 patients ...
Wang H - - 2000
Injection of the pineal indoles melatonin, 5-methoxytryptophol and 5-methoxytryptamine via the external jugular vein elicited a dose-dependent depression in mean arterial pressure. Melatonin and 5-methoxytryptophol were approximately equipotent and a dose of 150 micromol/kg brought about a reduction of about 40 mmHg in mean arterial pressure. Methoxytryptamine exerted a much ...
Geyer O - - 2000
PURPOSE: The aim of this study was to determine allergic responses to clonidine hydrochloride 0.25% in glaucoma patients with proven allergic reaction to apraclonidine 0.5%. METHODS: Fifteen consecutive glaucoma patients with allergic reaction to apraclonidine were prospectively challenged with clonidine hydrochloride 0.25% and evaluated for recurrence of allergic reactions and ...
Marinangeli F - - 2000
The study evaluated the effects of premedication with intravenous clonidine on thiopental or propofol requirements for induction and haemodynamic changes associated with both induction and endotracheal intubation. Clonidine administered intravenously before induction of anaesthesia reduced propofol or thiopental requirements. The association of clonidine and propofol caused, after injection of the ...
Roche W J - - 2000
Hypertension in the patient with SCI is relatively rare and generally restricted to patients with high-level injuries where autonomic dysreflexia can occur. Resting blood pressure in individuals with SCI has been described as lower than that in the normal population. This report describes five previously normotensive teenagers with subsequent paraplegia ...
Eisenach J C - - 1999
BACKGROUND: alpha2-Adrenergic agonists produce analgesia primarily by a spinal action and hypotension and bradycardia by actions at several sites. Clonidine is approved for epidural use in the treatment of neuropathic pain, but its wider application is limited by hemodynamic side effects. This study determined the antinociceptive and hemodynamic effects of ...
Petersson M - - 1999
Oxytocin treatment decreases blood pressure and changes the pattern of spontaneous motor activity. The aim of this study was to explore if alpha 2-adrenoreceptors that are involved in the regulation of blood pressure and spontaneous motor activity are influenced by oxytocin treatment. For this purpose, male rats were pretreated with ...
Goenka S - - 1999
We report a case of a neonate who developed hypotension immediately after birth, and needed dopamine infusion to sustain his blood pressure and tissue perfusion. He developed cyanosis of his extremity immediately after dopamine was started via peripheral line and improved spontaneously after dopamine was stopped. This happened repeatedly at ...
< 1 2 3 4 5 6 7 8 9 10 11 >