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150 result(s) for "Adrenergic alpha-2 Receptor Agonists - adverse effects"
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Clonidine in Patients Undergoing Noncardiac Surgery
In this trial, clonidine, an α2-adrenergic agonist, did not reduce the rate of death or MI among patients undergoing noncardiac surgery. Clonidine did increase the risk of perioperative hypotension, bradycardia, and nonfatal cardiac arrest. Myocardial infarction is the most common major vascular complication of surgery and is associated with substantial mortality. 1 During and after noncardiac surgery, there is marked activation of the sympathetic nervous system, which can lead to a mismatch between the supply of and demand for myocardial oxygen and to subsequent myocardial infarction. 2 – 4 We previously reported that perioperative administration of a high-dose, long-acting beta-blocker (initiated 2 to 4 hours before surgery and continued after surgery) reduced the risk of myocardial infarction but increased the risk of death, stroke, and clinically important hypotension. 5 Clonidine, an α 2 -adrenergic agonist, blunts central sympathetic . . .
The pharmacokinetics of dexmedetomidine in patients with obstructive jaundice: A clinical trial
Dexmedetomidine, a highly selective central α2-agonist, undergoes mainly biotransformation in the liver. The pharmacokinetics of dexmedetomidine were significantly affected by hepatic insufficiency. The clearance of dexmedetomidine in patients with severe hepatic failure decreased by 50% compared with controls. We tested the hypothesis that the pharmacokinetics of dexmedetomidine would be affected by obstructive jaundice. The prospective registration number of clinical trial is ChiCTR-IPR-15007572. 18 patients with obstructive jaundice and 12 non-jaundiced patient controls received dexmedetomidine, 1 μg/kg, over 10 min. Arterial blood samples were drawn before, during, and up to 5 h after the infusion. Plasma dexmedetomidine concentrations were determined by 1290 infinity high performance liquid chromatography coupled with 6470 tandem mass spectrometry. The relevant pharmacokinetic parameters were calculated by non-compartmental analysis using Phoenix WinNonlin 7.0. Plasma clearance of dexmedetomidine was decreased by 33.3% in the obstructive jaundice group as compared with the control group (0.0068±0.0017 vs. 0.0102±0.0033 L/kg/min; P = 0.002). Volume of distribution was decreased by 29.2% in the obstructive jaundice group as compared with the control group (1.43±0.58 vs. 2.02±0.84 L/kg; P = 0.041). This study demonstrates that the clearance and distribution volume of dexmedetomidine were decreased in patients with obstructive jaundice. It may be advisable to adjust the dose of dexmedetomidine in those patients.
Efficacy and Safety of Dexmedetomidine in the Prone Position in Elderly Patients with Pneumonia: A Prospective, Double-Blind, Randomized Controlled Study
Purpose We aimed to identify a safe and effective method to assist older adults with pneumonia in tolerating the prone position for a longer duration. Methods This was a randomized, controlled, double-blinded study performed at the Shanghai Fourth People's Hospital. Eighty patients with pneumonia aged ≥ 65 years were included. The patients were able to spontaneous breath in the prone position and were administered intravenous dexmedetomidine or an isotonic sodium chloride solution. The cumulative daily durations of prone positioning for all patients in the two groups were recorded. The primary outcome was the percentage of patients who completed ≥ 9 h/day in the prone position. The secondary outcomes included the incidence of complications in the prone position and patient outcomes. Results Eighty patients were included (average age: 79.6 ± 8.9 years). The percentage of patients who completed ≥ 9 h/day in the prone position was significantly higher in the dexmedetomidine group than in the placebo group ( P  = 0.011). The percentage of patients who completed ≥ 12 h/day in the prone position was also significantly greater in the dexmedetomidine group than in the placebo group ( P  = 0.008). There were no significant differences in other variables between the two groups. Conclusions The results of this study demonstrate that intravenous dexmedetomidine injection can significantly prolong the duration of spontaneous breathing in the prone position in elderly pneumonia patients without obvious adverse events. We provide a safe and effective method to help patients with pneumonia, especially those with delirium or cognitive impairment, who cannot tolerate the length of time needed for spontaneous breathing in the prone position to be effective. Trial registration: The study was registered with the Chinese Clinical Trial Center (registration number: ChiCRT2300067383) on 2023-01-05.
Sex Differences in Guanfacine Effects on Drug Craving and Stress Arousal in Cocaine-Dependent Individuals
Currently, no FDA-approved medication exists for the treatment of cocaine use disorder. Furthermore, as women become increasingly more at risk for the consequences of cocaine addiction, the need to establish better-tailored treatment medications is paramount. We examine the effects of the alpha2 adrenergic agonist, guanfacine HCl, on responses to stress and drug cue in a group of cocaine-dependent men and women who also abuse alcohol and nicotine. Forty early abstinent treatment-seeking cocaine-dependent males and females were randomly assigned to receive either daily placebo (12 M/7 F) or guanfacine (2 or 3 mg) (15 M/6 F) for 3 weeks. In week 4, they participated in a laboratory experiment and were exposed to three 10-min guided imagery conditions (stress/stress, cue/cue, and stress/cue), one per day, consecutively in a random, counterbalanced order. Craving, negative emotion, anxiety, and cardiovascular function were assessed at baseline, immediately following imagery exposure, and at various recovery time points. Guanfacine significantly attenuated cocaine craving, alcohol craving, anxiety, and negative emotion following exposure to all three imagery conditions in females, but not males. Guanfacine did, however, reduce sympathetic tone as well as stress and cue-induced nicotine craving and systolic blood pressure (SBP) in both males and females. These findings highlight sex-specific effects of guanfacine on drug craving, anxiety, and negative mood with significant effects in women and not men. The findings suggest further evaluation of guanfacine in the treatment of cocaine use disorder with a specific focus on sex differences in treatment response.
Extended Release Guanfacine in Pediatric Anxiety Disorders: A Pilot, Randomized, Placebo-Controlled Trial
Objective: This is a feasibility study evaluating the safety, tolerability, and potential anxiolytic efficacy of the α2 agonist guanfacine extended-release (GXR) in children and adolescents with generalized anxiety disorder (GAD), separation anxiety disorder (SAD), or social phobia/social anxiety disorder. Methods: Youth aged 6–17 years with a primary diagnosis of GAD, SAD, and/or social anxiety disorder were treated with flexibly dosed GXR (1–6 mg daily, n = 62) or placebo (n = 21) for 12 weeks. The primary aim of this study was to determine the safety and tolerability of GXR in youth with anxiety disorders, which involved the analysis of treatment-emergent adverse events (TEAEs), the emergence of suicidal ideation and behaviors, vital signs, and electrocardiographic/laboratory parameters. Exploratory efficacy measures included dimensional anxiety scales (Pediatric Anxiety Rating Scale [PARS] and Screen for Child Anxiety Related Emotional Disorders [SCARED]), as well as the Clinical Global Impression–Improvement (CGI-I) scale. As this was an exploratory study, no inferential statistical analyses were performed. Results: GXR was safe and well tolerated. Treatment-related mean ± standard deviation changes in heart rate (GXR: 1.8 ± 12 beats per minute [bpm] decrease; placebo: 0.5 ± 11 bpm decrease), systolic blood pressure (GXR: 2.3 ± 11 mm Hg decrease; placebo: 1.7 ± 11 mm Hg decrease), or diastolic blood pressure (GXR: 1.3 ± 9 mm Hg decrease; placebo: 0.9 ± 7 mm Hg increase) were similar between treatment groups. TEAEs, including headache, somnolence/fatigue, abdominal pain, and dizziness, were consistent with the known safety profile of GXR. No differences were observed between treatment groups for PARS and SCARED scores, although at endpoint, a higher proportion of subjects receiving GXR versus placebo demonstrated CGI-I scores ≤2 (54.2% vs. 31.6%), as rated by the clinician investigator. Conclusions: GXR was well tolerated in pediatric subjects with GAD, SAD, and/or social anxiety disorder. ClinicalTrials.gov Identifier: NCT01470469.
Effect of dexmedetomidine on perioperative blood glucose regulation in type 2 diabetic patients undergoing laparoscopic colorectal cancer radical resection: a randomised double-blinded controlled trial
Background The stability of blood glucose levels in diabetic patients is more susceptible to fluctuations than in nondiabetic individuals. The effect of dexmedetomidine on glucose fluctuations in diabetic patients remains unclear. This study aimed to investigate the effect of intraoperative dexmedetomidine on glucose homeostasis in patients with type 2 diabetes undergoing laparoscopic colorectal cancer radical resection. Methods 80 participants with T2DM preparing for laparoscopic colorectal cancer radical resection were randomly divided into four groups: control group (group C), dexmedetomidine 1 μg ⋅ kg −1  + 0.25 μg ⋅ kg −1 ⋅ h −1 (group D1), 1 μg ⋅ kg −1  + 0.5 μg ⋅ kg −1 ⋅ h −1 (group D2), and 1 μg ⋅ kg −1  + 0.75 μg ⋅ kg −1 ⋅ h −1 (group D3). Levels of blood glucose were measured before the intravenous infusion of dexmedetomidine (T1), 15 min after the intubation(T2), 1 h after the beginning of the surgery (T3), at the end of the surgery (T4), and 30 min after the extubation in PACU (T5). Results Compared with the baseline levels, the levels of blood glucose from T2 to T5 in group C increased gradually but were not significantly different at each time point ( p  > 0.05), and there was a statistically significant rise in blood glucose in group D1 at T3, T4, and T5 and in groups D2 and D3 at T2, T3, and T4 ( p  < 0.05). Compared with group C, blood glucose in groups D2 and D3 was significantly higher at T3, andT4 ( p  < 0.05). Compared with group C, the rangeability from T1 to T3 and T1 to T4 was significantly higher in groups D2 and D3 ( p  < 0.05). Conclusion Dexmedetomidine loading dose 1 μg/kg and a Maintenance dose 0.25 μg/kg/h can be used in type 2 diabetic patients for better glucose regulation without increasing the incidence of perioperative hyperglycemia, adverse effects, and extending extubation time. Trial registration ChiCTR2100042050. Registered on January 13, 2021, with ChiCTR. https://www.chictr.org.cn/showproj.html?proj=120133 .
Randomized clinical trial to compare the efficacy to improve the quality of surgical field of hypotensive anesthesia with clonidine or dexmedetomidine during functional endoscopic sinus surgery
Purpose Intense bleeding of the surgical field is a potential factor influencing success of functional endoscopic sinus surgery (FESS). Hypotensive anesthesia with α2 intravenous agonists reduces intraoperative bleeding, but which is the best agent is unknown. The main objective of this trial was to compare the current standard adjuvant drug for hypotensive anesthesia, clonidine, with the recently available alternative dexmedetomidine. Methods A randomized clinical trial compared the efficacy of clonidine and dexmedetomidine during FESS. Treatment was open label for the anesthesiologist and operating surgeon, but blind for an external evaluator who evaluated video-recorded surgeries. A Boezaart scale was assessed every 30 min during FESS until surgery completion. Main end-point was the proportion of patients with mean Boezaart scores > 2 (heavy bleeding) by external blinded evaluator. Secondary end-points included other bleeding parameters, surgery duration, hemodynamic measures and surgical complications. Results 94 patients were randomized. There were no significant differences in the proportion of patients with mean Boezaart scores > 2 in clonidine (42.6%) and dexmedetomidine (42.6%). Consistently, no differences were observed in secondary variables of bleeding, duration or complications. Small differences in mean heart rate were observed that might reflect different pharmacological profiles of the products, but are of uncertain clinical relevance. Conclusions No significant differences were observed between clonidine and dexmedetomidine when used as anesthetic adjuvants in the reduction of surgical bleeding in FESS. A longer experience with clonidine and its lower costs suggest it may be a preferable option as an adjuvant for hypotensive anesthesia.
Efficacy of a single dose of dexmedetomidine for cough suppression during anesthetic emergence: a randomized controlled trial
Purpose Maintenance of a remifentanil infusion during anesthetic emergence has been reported to decrease the incidence of coughing and thereby help to ensure a smooth emergence. It may, however, cause respiratory depression and possibly delay emergence. The purpose of this study was to investigate the effect of a single dose of dexmedetomidine combined with a low-dose remifentanil infusion on cough suppression during emergence from general anesthesia. Methods American Society of Anesthesiologists physical status I-II adults undergoing elective thyroidectomy under sevoflurane anesthesia were recruited and randomly allocated to receive either dexmedetomidine 0.5 μg·kg −1 iv (Group D, n  = 70) or saline (Group S, n  = 71), each combined with a low-dose remifentanil infusion ten minutes before the end of surgery. Coughing was assessed using a four-point scale. The respiratory rate (RR), heart rate (HR), and mean arterial pressure were also recorded. Results The incidence of coughing was lower in Group D than in Group S (64% vs 91%, respectively; mean difference 27%; 95% confidence interval [CI] 13 to 41; P  < 0.001). The median cough grade at extubation was also lower in Group D. Mean arterial pressure and HR were elevated in Group S during tracheal extubation but were similar to baseline values in Group D. There was no difference in RR between the two groups throughout the study. A small delay in extubation was observed in Group D (3 minutes longer than Group S; 95% CI 2 to 4; P  < 0.001). Conclusion Compared with an infusion of low-dose remifentanil alone, the addition of a single dose (0.5 μg·kg −1 ) of dexmedetomidine during emergence from sevoflurane-remifentanil anesthesia was effective in attenuating coughing and hemodynamic changes and did not exacerbate respiratory depression after thyroid surgery. This trial was registered at Clinicaltrial.gov, identifier: NCT01774305.
Decreasing adrenergic or sympathetic hyperactivity after severe traumatic brain injury using propranolol and clonidine (DASH After TBI Study): study protocol for a randomized controlled trial
Background Severe TBI, defined as a Glasgow Coma Scale ≤ 8, increases intracranial pressure and activates the sympathetic nervous system. Sympathetic hyperactivity after TBI manifests as catecholamine excess, hypertension, abnormal heart rate variability, and agitation, and is associated with poor neuropsychological outcome. Propranolol and clonidine are centrally acting drugs that may decrease sympathetic outflow, brain edema, and agitation. However, there is no prospective randomized evidence available demonstrating the feasibility, outcome benefits, and safety for adrenergic blockade after TBI. Methods/Design The DASH after TBI study is an actively accruing, single-center, randomized, double-blinded, placebo-controlled, two-arm trial, where one group receives centrally acting sympatholytic drugs, propranolol (1 mg intravenously every 6 h for 7 days) and clonidine (0.1 mg per tube every 12 h for 7 days), and the other group, double placebo, within 48 h of severe TBI. The study uses a weighted adaptive minimization randomization with categories of age and Marshall head CT classification. Feasibility will be assessed by ability to provide a neuroradiology read for randomization, by treatment contamination, and by treatment compliance. The primary endpoint is reduction in plasma norepinephrine level as measured on day 8. Secondary endpoints include comprehensive plasma and urine catecholamine levels, heart rate variability, arrhythmia occurrence, infections, agitation measures using the Richmond Agitation-Sedation Scale and Agitated Behavior scale, medication use (anti-hypertensive, sedative, analgesic, and antipsychotic), coma-free days, ventilator-free days, length of stay, and mortality. Neuropsychological outcomes will be measured at hospital discharge and at 3 and 12 months. The domains tested will include global executive function, memory, processing speed, visual-spatial, and behavior. Other assessments include the Extended Glasgow Outcome Scale and Quality of Life after Brain Injury scale. Safety parameters evaluated will include cardiac complications. Discussion The DASH After TBI Study is the first randomized, double-blinded, placebo-controlled trial powered to determine feasibility and investigate safety and outcomes associated with adrenergic blockade in patients with severe TBI. If the study results in positive trends, this could provide pilot evidence for a larger multicenter randomized clinical trial. If there is no effect of therapy, this trial would still provide a robust prospective description of sympathetic hyperactivity after TBI. Trial registration ClinicalTrials.gov NCT01322048
Dexmedetomidine Dose Dependently Enhances the Local Anesthetic Action of Lidocaine in Inferior Alveolar Nerve Block: A Randomized Double-Blind Study
Background and ObjectivesDexmedetomidine (DEX) dose dependently enhances the local anesthetic action of lidocaine in rats. We hypothesized that the effect might also be dose dependent in humans. We evaluated the effect of various concentrations of DEX with a local anesthetic in humans.MethodsEighteen healthy volunteers were randomly assigned by a computer to receive 1.8 mL of 1 of 4 drug combinations: (1) 1% lidocaine with 2.5 ppm (parts per million) (4.5 μg) DEX, (2) lidocaine with 5.0 ppm (9.0 μg) DEX, (3) lidocaine with 7.5 ppm (13.5μg) DEX, or (4) lidocaine with 1:80,000 (22.5 μg) adrenaline (AD), to produce inferior alveolar nerve block. Pulp latency and lower lip numbness (for assessing onset and duration of anesthesia) were tested, and sedation level, blood pressure, and heart rate were recorded every 5 minutes for 20 minutes, and every 10 minutes from 20 to 60 minutes.ResultsPulp latency of each tooth increased compared with baseline, from 5 to 15 minutes until 60 minutes. There were no significant intergroup differences at any time point. Anesthesia onset was not different between groups. Anesthesia duration was different between groups (that with DEX 7.5 ppm was significantly longer than that with DEX 2.5 ppm and AD; there was no difference between DEX 2.5 ppm and AD). Blood pressure decreased from baseline in the 5.0 and 7.5 ppm DEX groups at 30 to 60 minutes, although there was no hypotension; moreover, heart rate did not change in any group. Sedation score did not indicate deep sedation in any of the groups.ConclusionsDexmedetomidine dose dependently enhances the local anesthetic action of lidocaine in humans. Dexmedetomidine at 2.5 ppm produces similar enhancement of local anesthesia effect as addition of 1:80,000 AD.