Dexmedetomidine Pretreatment Confers Myocardial Protection and Reduces Mechanical Ventilation Duration for Patients Undergoing Cardiac Valve Replacement under Cardiopulmonary Bypass.

PURPOSE: The study aims to assess the effects of dexmedetomidine (Dex) pretreatment on patients during cardiac valve replacement under cardiopulmonary bypass. METHODS: For patients in the Dex group (n = 52), 0.5 µg/kg Dex was given before anesthesia induction, followed by 0.5 µg/kg/h pumping injection before aortic occlusion. For patients in the control group (n = 52), 0.125 ml/kg normal saline was given instead of Dex. RESULTS: The patients in the Dex group had longer time to first dose of rescue propofol than the control group (P = 0.003). The Dex group required less total dosage of propofol than the control group (P = 0.0001). The levels of cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) were lower in the Dex group than the control group at T4, 8 h after the operation (T5), and 24 h after the operation (T6) (P <0.01). The Dex group required less time for mechanical ventilation than the control group (P = 0.003). CONCLUSION: The study suggests that 0.50 µg/kg Dex pretreatment could reduce propofol use and the duration of mechanical ventilation, and confer myocardial protection without increased adverse events during cardiac valve replacement.

A case of pulmonary edema due to guanfacine intoxication with measurement of serum guanfacine concentrations.

Guanfacine hydrochloride extended-release (GXR) is used to treat attention deficit hyperactivity disorder. It is a selective α2A-adrenorecepor agonist that was reported to cause QT prolongation and hypotension in the event of overdosing. We report the case of a 17-year-old man who took 226 tablets of GXR 3 mg for attempted suicide. He was found complaining of dyspnea, and emergency medical services were called. When the patient was transferred to our hospital, his Glasgow coma scale was 12 (E4V3M5). He was agitated and hypoxemic. He was intubated for invasive mechanical ventilation under sedation. His chest X-ray and computed tomography scan showed pulmonary edema. Transthoracic echocardiography showed markedly reduced cardiac function. His serum guanfacine concentration peaked on day 3 after admission. His pulmonary edema improved quickly after a decrease in serum guanfacine concentration, but cardiac decompensation persisted for about 1 month. This case reveals that the decline in cardiac function after guanfacine intoxication is prolonged even after its serum concentration has decreased.

[Alpha-2 adrenoreceptor agonists for the intensive care physician]. / Les agonistes α2-adrénergiques pour l'intensiviste.

Clonidine and dexmedetomidine are two α2-adrenoreceptors agonists available for the intensivist in the clinical practice. The affinity of dexmedetomidine is eight times greater than clonidine affinity for the α2 receptors. Their main effect is sedation. They act by inhibition of noradrenaline release in the locus coeruleus in the brainstem. α2-agonists are used primarily for sedation, analgesia, and management of delirium. Nowadays, dexmedetomidine application is increasing in critically ill patients showing a good safety. Most frequent side effects include bradycardia and hypotension.

En pratique clinique, l'intensiviste dispose de deux α2-agonistes, à savoir la clonidine et la dexmédétomidine. L'affinité de la dexmédétomidine pour les récepteurs α2-adrénergiques est huit fois plus importante que celle de la clonidine. Leur principal effet est la sédation. Cet effet est obtenu par inhibition de la libération de noradrénaline dans le locus cœruleus du tronc cérébral. Ces molécules sont surtout utilisées pour la sédation, l'analgésie et la prise en charge du delirium chez le patient critique. Le recours à la dexmédétomidine augmente actuellement et montre une bonne sécurité de la molécule. Les effets indésirables les plus fréquents sont la bradycardie et l'hypotension.

Effect of Sublingual Dexmedetomidine vs Placebo on Acute Agitation Associated With Bipolar Disorder: A Randomized Clinical Trial.

Importance: Acute agitation is common in patients with bipolar disorder and requires urgent management to relieve distress and to prevent escalation to aggressive behavior. Objective: To evaluate the effect of orally absorbed, sublingual dexmedetomidine, a selective α2A-adrenergic receptor agonist on symptoms of acute agitation in patients with bipolar disorder. Design, Setting, and Participants: Phase 3, randomized, double-blind, placebo-controlled trial conducted in 15 sites in the US with enrollment between February 24, 2020, and April 27, 2020, and final follow-up on May 21, 2020. A total of 380 adults with bipolar I or II disorder were randomized and 362 completed the study. Interventions: Participants were randomized to 3 groups: sublingual dexmedetomidine 180 µg (n = 127), sublingual dexmedetomidine 120 µg (n = 127), or placebo (n = 126). Main Outcomes and Measures: The primary efficacy end point was the mean change from baseline at 2 hours for the Positive and Negative Syndrome Scale-Excited Component (PEC) total score. The range of possible total scores is 5 (absence of agitation) to 35 (extremely severe). The secondary end point was the earliest time of a statistically significant change in PEC total score from baseline for the drug vs placebo. On the primary efficacy end point, to account for multiplicity associated with comparing 2 sublingual dexmedetomidine doses with placebo, the 2-sided significance level for each dose vs placebo was set at .025. Results: Of 380 patients randomized (mean age, 45.6 years; 54.8% women; and 56.1% Black individuals), 378 (99.5%) self-administered the study medication and completed the study. Baseline agitation was mild to moderate, with an overall mean PEC total score of 18.0. Two hours after taking the medication, the mean changes from baseline in PEC total score were -10.4 for sublingual dexmedetomidine 180 µg, -9.0 for sublingual dexmedetomidine 120 µg, and -4.9 for placebo. Least-square mean differences from placebo in the sublingual dexmedetomidine groups at 2 hours were -5.4 (97.5% CI, -6.6 to -4.2) for 180 µg and -4.1 (97.5% CI, -5.3 to -2.9) for 120 µg (both doses P < .001 vs placebo). Treatment effects began 20 minutes after taking the medication among patients in the sublingual dexmedetomidine groups (least-square mean difference for 180 µg, -1.1 [97.5% CI, -2.0 to -0.2]; P = .007; for 120 µg, -1.0 [97.5% CI, -1.9 to -0.1]; P = .009). Adverse events occurred in 35.7% of patients taking 180 µg of dexmedetomidine, 34.9% taking 120 µg, and 17.5% taking placebo. The most common adverse events (≥5%) in the respective 180 µg, 120 µg, and placebo groups were somnolence (21.4% and 20.6% vs 4.8%); dry mouth (4.8% and 7.1% vs 0.8%); hypotension (6.3% and 4.8% vs 0%); and dizziness (5.6% and 5.6% vs 0.8%). Conclusions and Relevance: Among patients with mild to moderate agitation associated with bipolar disorder, treatment with a sublingual film formulation of dexmedetomidine 120 µg or 180 µg, compared with placebo, resulted in significantly greater reduction in the agitation score at 2 hours. Further research is needed to understand the spectrum of patients for whom this treatment would be effective and feasible and to better understand the clinical importance of the observed effect size. Trial Registration: ClinicalTrials.gov Identifier: NCT04276883.

Preliminary evaluation of the efficacy and safety of brimonidine for general anesthesia.

BACKGROUND: To determine the hypnotic and analgesic effects of brimonidine, and evaluate its efficacy and safety for general anesthesia. Potentiation of pentobarbital sleeping time following brimonidine administration was observed in mice, as was the analgesic activity of brimonidine. METHODS: The median effective dose (ED50) and lethal dose (LD50) of intraperitoneally injected brimonidine were determined in hypnotized mice. In addition, the LD50 of intravenously injected brimonidine, and ED50 of intravenously, intramuscularly, and intrarectally injected brimonidine in hypnotized rabbits were determined. Finally, the synergistic anesthetic effect of brimonidine and chloral hydrate was evaluated in rabbits. RESULTS: Intraperitoneal injection of 10 mg/kg brimonidine enhanced the hypnotic effect of a threshold dose of pentobarbital. Intraperitoneally injected brimonidine produced dose-related analgesic effects in mice. The ED50 of intraperitoneally administered brimonidine in hypnotized mice was 75.7 mg/kg and the LD50 was 379 mg/kg. ED50 values of intravenous, intramuscular, and intrarectal brimonidine for hypnosis in rabbits were 5.2 mg/kg, 8.8 mg/kg, and 8.7 mg/kg, respectively; the LD50 of intravenous brimonidine was 146 mg/kg. Combined intravenous administration of 0.6 mg/kg brimonidine and 0.03 g/kg chloral hydrate had a synergistic anesthetic effect. CONCLUSIONS: Brimonidine elicited hypnotic and analgesic effects after systemic administration and exhibited safety. Moreover, brimonidine enhanced the effects of other types of narcotics when combined.

Strategies to Prevent Acute Kidney Injury after Pediatric Cardiac Surgery: A Network Meta-Analysis.

BACKGROUND AND OBJECTIVES: AKI is a common complication after pediatric cardiac surgery and has been associated with higher morbidity and mortality. We aimed to compare the efficacy of available pharmacologic and nonpharmacologic strategies to prevent AKI after pediatric cardiac surgery. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: PubMed/MEDLINE, Embase, Cochrane Controlled Trials Register, and reference lists of relevant articles were searched for randomized controlled trials from inception until August 2020. Random effects traditional pairwise, Bayesian network meta-analyses, and trial sequential analyses were performed. RESULTS: Twenty randomized controlled trials including 2339 patients and 11 preventive strategies met the eligibility criteria. No overall significant differences were observed compared with control for corticosteroids, fenoldopam, hydroxyethyl starch, or remote ischemic preconditioning in traditional pairwise meta-analysis. In contrast, trial sequential analysis suggested a 80% relative risk reduction with dexmedetomidine and evidence of <57% relative risk reduction with remote ischemic preconditioning. Nonetheless, the network meta-analysis was unable to demonstrate any significant differences among the examined treatments, including also acetaminophen, aminophylline, levosimendan, milrinone, and normothermic cardiopulmonary bypass. Surface under the cumulative ranking curve probabilities showed that milrinone (76%) was most likely to result in the lowest risk of AKI, followed by dexmedetomidine (70%), levosimendan (70%), aminophylline (59%), normothermic cardiopulmonary bypass (57%), and remote ischemic preconditioning (55%), although all showing important overlap. CONCLUSIONS: Current evidence from randomized controlled trials does not support the efficacy of most strategies to prevent AKI in the pediatric population, apart from limited evidence for dexmedetomidine and remote ischemic preconditioning.

A Multicentric, Randomized, Controlled Phase III Study of Centhaquine (Lyfaquin®) as a Resuscitative Agent in Hypovolemic Shock Patients.

INTRODUCTION: Centhaquine (Lyfaquin®) showed significant safety and efficacy in preclinical and clinical phase I and II studies. METHODS: A prospective, multicentric, randomized phase III study was conducted in patients with hypovolemic shock, systolic blood pressure (SBP) ≤ 90 mmHg, and blood lactate levels ≥ 2 mmol/L. Patients were randomized in a 2:1 ratio to the centhaquine group (n = 71) or the control (saline) group (n = 34). Every patient received standard of care (SOC) and was followed for 28 days. The study drug (normal saline or centhaquine 0.01 mg/kg) was administered in 100 mL of normal saline infusion over 1 h. The primary objectives were to determine changes (mean through 48 h) in SBP, diastolic blood pressure (DBP), blood lactate levels, and base deficit. The secondary objectives included the amount of fluids, blood products, and vasopressors administered in the first 48 h, duration of hospital stay, time in intensive care units, time on ventilator support, change in acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), and the proportion of patients with 28-day all-cause mortality. RESULTS: The demographics of patients and baseline vitals in both groups were comparable. The cause of hypovolemic shock was trauma in 29.4 and 47.1% of control group and centhaquine group patients, respectively, and gastroenteritis in 44.1 and 29.4%, respectively. Shock index (SI) and quick sequential organ failure assessment at baseline were similar in the two groups. An equal amount of fluids and blood products were administered in both groups during the first 48 h of resuscitation. A lesser amount of vasopressors was needed in the first 48 h of resuscitation in the centhaquine group. An increase in SBP from baseline was consistently higher up to 48 h (12.9% increase in area under the curve from 0 to 48 h [AUC0-48]) in the centhaquine group than in the control group. A significant increase in pulse pressure (48.1% increase in AUC0-48) in the centhaquine group compared with the control group suggests improved stroke volume due to centhaquine. The SI was significantly lower in the centhaquine group from 1 h (p = 0.032) to 4 h (p = 0.049) of resuscitation. Resuscitation with centhaquine resulted in a significantly greater number of patients with improved blood lactate (control 46.9%; centhaquine 69.3%; p = 0.03) and the base deficit (control 43.7%; centhaquine 69.8%; p = 0.01) than in the control group. ARDS and MODS improved with centhaquine, and an 8.8% absolute reduction in 28-day all-cause mortality was observed in the centhaquine group. CONCLUSION: Centhaquine is an efficacious resuscitative agent for treating hypovolemic shock. The efficacy of centhaquine in distributive shock is being explored. TRIAL REGISTRATION: Clinical Trials Registry, India; ctri.icmr.org.in, CTRI/2019/01/017196; clinicaltrials.gov, NCT04045327.

Evaluating Guanfacine Hydrochloride in the Treatment of Attention Deficit Hyperactivity Disorder (ADHD) in Adult Patients: Design, Development and Place in Therapy.

Attention-deficit/hyperactivity disorder (ADHD) is characterized by age-inappropriate and impairing levels of inattention, hyperactivity, or impulsivity, or a combination of these characteristics. It is estimated to affect around 4% of adults worldwide. In the past few decades, prescriptions for ADHD drugs (psychostimulants and non-psychostimulants) have increased significantly. However, the efficacy and safety of adult ADHD medications remains controversial. Guanfacine extended-release (GXR) is a non-psychostimulant ADHD drug that is a selective α2A-adrenergic receptor agonist, first approved for treatment of adult ADHD in Japan in June 2019. Our aim was to provide an overview of GXR pharmacology and review the studies on efficacy and safety that have been conducted in adults with ADHD. The beneficial actions of guanfacine are thought to be attributed to the strengthening of prefrontal cortical network connections, which regulate attention, emotion, and behavior via the activity at post-synaptic α2A receptors. Current evidence of GXR efficacy and safety suggests that GXR is an effective monotherapy treatment option for adults with ADHD.

α2-Adrenergic Agonists or Stimulants for Preschool-Age Children With Attention-Deficit/Hyperactivity Disorder.

Importance: Attention-deficit/hyperactivity disorder (ADHD) is diagnosed in approximately 2.4% of preschool-age children. Stimulants are recommended as first-line medication treatment. However, up to 25% of preschool-age children with ADHD are treated with α2-adrenergic agonist medications, despite minimal evidence about their efficacy or adverse effects in this age range. Objective: To determine the frequency of reported improvement in ADHD symptoms and adverse effects associated with α2-adrenergic agonists and stimulant medication for initial ADHD medication treatment in preschool-age children. Design, Setting, and Participants: Retrospective electronic health record review. Data were obtained from health records of children seen at 7 outpatient developmental-behavioral pediatric practices in the Developmental Behavioral Pediatrics Research Network in the US. Data were abstracted for 497 consecutive children who were younger than 72 months when treatment with an α2-adrenergic agonist or stimulant medication was initiated by a developmental-behavioral pediatrician for ADHD and were treated between January 1, 2013, and July 1, 2017. Follow-up was complete on February 27, 2019. Exposures: α2-Adrenergic agonist vs stimulant medication as initial ADHD medication treatment. Main Outcomes and Measures: Reported improvement in ADHD symptoms and adverse effects. Results: Data were abstracted from electronic health records of 497 preschool-age children with ADHD receiving α2-adrenergic agonists or stimulants. Median child age was 62 months at ADHD medication initiation, and 409 children (82%) were males. For initial ADHD medication treatment, α2-adrenergic agonists were prescribed to 175 children (35%; median length of α2-adrenergic agonist use, 136 days) and stimulants were prescribed to 322 children (65%; median length of stimulant use, 133 days). Improvement was reported in 66% (95% CI, 57.5%-73.9%) of children who initiated α2-adrenergic agonists and 78% (95% CI, 72.4%-83.4%) of children who initiated stimulants. Only daytime sleepiness was more common for those receiving α2-adrenergic agonists vs stimulants (38% vs 3%); several adverse effects were reported more commonly for those receiving stimulants vs α2-adrenergic agonists, including moodiness/irritability (50% vs 29%), appetite suppression (38% vs 7%), and difficulty sleeping (21% vs 11%). Conclusions and Relevance: In this retrospective review of health records of preschool-age children with ADHD treated in developmental-behavioral pediatric practices, improvement was noted in the majority of children who received α2-adrenergic agonists or stimulants, with differing adverse effect profiles between medication classes. Further research, including from randomized clinical trials, is needed to assess comparative effectiveness of α2-adrenergic agonists vs stimulants.

Evaluation of ropivacaine combined with dexmedetomidine versus ropivacaine alone for epidural anesthesia: A meta-analysis.

BACKGROUND: Ropivacaine is considered the most commonly used for epidural anesthesia. We compared the efficiency and safety of ropivacaine alone (R group) and ropivacaine combined with dexmedetomidine (RD group). METHOD: PubMed, the Cochrane Library, Google Scholar, Ovid Medline, the Web of Science, Scopus, Embase, and ScienceDirect were searched. We considered sensory and motor block, duration of anesthesia, time to rescue, hemodynamics, and adverse effects as the primary endpoints. RESULTS: Eleven randomized controlled trials were included with 337 patients in the R group and 336 patients in the RD group. The RD group had a shorter time to onset of sensory (mean difference [MD]: 3.97 [1.90-6.04] minutes; P = .0002) and motor (MD: 2.43 [0.70-4.16] minutes; P = .006) block and a longer duration of anesthesia (MD: -164.17 [-294.43 to -33.91]; P = .01) than the R group. Comparison of the time to rescue between the groups showed no significant difference (MD: -119.01[-254.47-16.46] minutes; P = 0.09). The R group showed more stable hemodynamics than the RD group in heart rate and arterial pressure at 10 minutes. The R group had a lower incidence of bradycardia and a higher incidence of shivering than the RD group. CONCLUSION: RD may be a more suitable choice for epidural anesthesia with better anesthetic outcomes than R alone. However, the safety of the combination must be carefully assessed.

Application of α2 -adrenergic agonists combined with anesthetics and their implication in pulmonary intravascular macrophages-insulted pulmonary edema and hypoxemia in ruminants.

Alpha2 -adrenergic agonists have been implicated in the development of pulmonary edema (PE) and sustained hypoxemia that lead to life-threatening pulmonary distress in ruminants, especially with sensitive and compromised animals. Recently, there is limited understanding of exact mechanism underlying pulmonary alterations associated with α2 -adrenergic agonist administration. Ruminants have a rich population of pulmonary intravascular macrophages (PIMs) in the pulmonary circulation, which may be involved in the development of pulmonary alveolo-capillary barrier damage. Hence, the central thesis of this review is overviewing the literatures regarding the systemic use of α2 -adrenergic agonists in domestic ruminants, focusing on their pulmonary side effects, especially on the influence of PIMs on the lung. At this moment, further studies are needed to provide a clear emphasis and better understanding of the potential role of PIMs in the lung pathophysiology associated with α2 -adrenergic agonists. These preliminary studies would be potentially to develop future medications and intervention targets that may be helpful to alleviate or prevent the critical striking pulmonary effects, and thereby improving the safety of α2 -agonist application in ruminants.

The Results of Preoperative Use of Topical Brimonidine in Strabismus Surgery.

Purpose: In this study, we wanted to retrospectively evaluate the effect of the use of topical brimonidine on intraoperative bleeding and surgical hemostasis before strabismus surgery. Methods: Brimonidine tartrate 0.15% (Brimogut, Bilim Ilac, Turkey) eye drops were applied 6 and 3 min before surgery to 44 eyes of 22 patients in group 1 for vasoconstriction. Drops were not applied to 46 eyes of 23 patients in group 2. Preoperative and postoperative photographs and video images were taken. Black-and-white images were used to define the surface areas of the blood vessels. The surface area was calculated by counting the black pixels with ImageJ software. Results: In group 1, redness of eye was observed, on average, at preoperative 339.25 ± 11.52 pixels and intraoperative 247.93 ± 10.63 pixels (P < 0.001). But there was no change in group 2 (preoperative 338.87 ± 8.45 pixels to intraoperative 339.71 ± 9.52 pixels, P > 0.05). The incidence of intraoperative bleeding evaluated by the number of eyes on which cautery was used shows that it was significantly less in group 1 than in group 2 (P < 0.001). Conclusions: The use of topical brimonidine before strabismus surgery facilitates clear monitoring of anatomical structures during surgery by effectively controlling hemorrhage. In the postoperative period, it significantly reduces subconjunctival hemorrhage.

Coadministration of tizanidine and ciprofloxacin: a retrospective analysis of the WHO pharmacovigilance database.

PURPOSE: Tizanidine, an alpha-adrenergic substance with antinociceptive and antihypertensive effects, is extensively metabolized via cytochrome P450 (CYP) 1A2. Therefore, coadministration with potent CYP1A2 inhibitors, such as ciprofloxacin, is contraindicated. However, both drugs are broadly utilized in various countries. Their concomitant use bears an inherent high risk for clinically significant symptoms, especially in multimorbid patients experiencing polypharmacy. This study aims to investigate the impact of coadministration of tizanidine and ciprofloxacin using real-world pharmacovigilance data and to raise awareness of this potentially underestimated safety issue. METHODS: We conducted a retrospective study including Individual Case Safety Reports (ICSR) registered until March 1, 2017, in the World Health Organization (WHO) global database. Demographic data, drug administration information, the course of the adverse drug reaction (ADR), its severity, and outcomes were analyzed for cases reporting ciprofloxacin comedication. RESULTS: In 91 (2.0%) of the identified 4192 worldwide ICSR on tizanidine, coadministration of ciprofloxacin was reported. Most of the patients were female (n = 59, 64.8%) with a median age of 54 years (range 13-85 years). The countries contributing most reports were the USA (n = 54, 59.3%) and Switzerland (n = 16, 17.6%). ADRs reported most often affected the nervous system and the cardiac function, especially with large tizanidine doses or drugs with CNS and cardiovascular depressant effects. In two cases, a fatal outcome was reported. CONCLUSION: Despite the existing formal contraindication, the concomitant use of tizanidine and ciprofloxacin can be observed in real-world clinical practice. Reactions mainly affected the central nervous and the cardiovascular system resulting in potentially severe adverse effects. The concomitant use of tizanidine and ciprofloxacin should absolutely be avoided.

Brinzolamide/brimonidine fixed-dose combination bid as an adjunct to a prostaglandin analog for open-angle glaucoma/ocular hypertension.

PURPOSE: To evaluate the additive intraocular pressure-lowering effect of twice-daily brinzolamide 1%/brimonidine 0.2% fixed-dose combination (BBFC) as an adjunct to a prostaglandin analog (PGA) in patients with open-angle glaucoma or ocular hypertension insufficiently controlled with PGA monotherapy. METHODS: In this Phase 4, double-masked trial, patients aged ⩾18 years, with a mean intraocular pressure of ⩾19 and <32 mm Hg in at least one eye were randomized (1:1) to receive BBFC + PGA (n = 96) or vehicle + PGA (n = 92) for 6 weeks. The primary endpoint was the mean change in diurnal intraocular pressure from baseline (averaged over 09:00 and 11:00 h) at Week 6. RESULTS: The mean diurnal intraocular pressure at baseline was similar in the BBFC + PGA (22.8 mm Hg) and vehicle + PGA (22.9 mm Hg) groups. The least squares mean change in diurnal intraocular pressure from baseline at Week 6 was greater with BBFC + PGA (-5.59 mm Hg (95% confidence interval: -6.2 to -5.0)) than with vehicle + PGA (-2.15 mm Hg (95% confidence interval: -2.7 to -1.6)); the treatment difference was statistically significant in favor of BBFC + PGA (-3.44 mm Hg, (95% confidence interval: -4.2 to -2.7); p < 0.001). Ocular adverse events were reported in 21.1% and 8.7% of patients in the BBFC + PGA and vehicle + PGA groups, respectively. The most frequent ocular adverse event was ocular hyperemia (5.3%) in the BBFC + PGA group and blurred vision (2.2%) in the vehicle + PGA group. CONCLUSION: BBFC + PGA significantly reduced mean diurnal intraocular pressure than PGA alone in patients with open-angle glaucoma or ocular hypertension. The safety findings with BBFC + PGA were consistent with the known safety profile of the individual medications.

Effects of an Intraoperative Intravenous Bolus Dose of Dexmedetomidine on Remifentanil-Induced Postinfusion Hyperalgesia in Patients Undergoing Thyroidectomy: A Double-Blind Randomized Controlled Trial.

BACKGROUND: Consecutive exposure to high-dose remifentanil during anesthesia may induce remifentanil-induced postinfusion hyperalgesia (RPH). Dexmedetomidine, a highly selective α2-adrenergic receptor agonist, may have synergistic effects with opioids and aid in perioperative pain management. In this study, we hypothesized that an intraoperative bolus dose of intravenous dexmedetomidine could alleviate RPH in patients undergoing thyroidectomy under general anesthesia. METHODS: Ninety patients undergoing thyroidectomy were randomly assigned to 1 of 3 groups: placebo, normal saline (group P); low-dose dexmedetomidine 0.2 µg·kg-1 (group LD); or high-dose dexmedetomidine 0.5 µg·kg-1 (group HD). Remifentanil was infused at a rate of 0.30 µg·kg-1·minute-1. Mechanical pain thresholds were measured using an Electronic von Frey device preoperatively and at 30 minutes, 6 hours, 24 hours, and 48 hours after surgery and were analyzed with 2-way repeated-measures analysis of variance (ANOVA) followed by Bonferroni post hoc comparison. We also recorded postoperative pain scores, the incidence of receiving rescue analgesics, and side effects up to 48 hours after surgery. RESULTS: The mechanical pain thresholds around the skin incision were significantly higher in group LD compared to group P 30 minutes and 6 hours after surgery (mean ± standard deviation: [65.0 ± 25.2] vs [49.6 ± 24.4] g, mean difference [95% confidence interval]: 15.4 [0.3-30.5] g, P = .045 at 30 minutes; [65.9 ± 24.5] vs [49.3 ± 26.1] g, 16.6 [1.1-32.1] g, P = .032 at 6 hours). The pain thresholds around the skin incision were significantly higher in group HD compared to group P 30 minutes and 6 hours after surgery ([67.8 ± 21.7] vs [49.6 ± 24.4] g, 18.2 [3.1-33.3] g, P = .013 at 30 minutes; [68.3 ± 22.5] vs [49.3 ± 26.1] g, 19.0 [3.5-34.5] g, P = .011 at 6 hours). The incidence of hyperalgesia around the skin incision was lower in group HD than in group P 30 minutes and 6 hours after surgery (4 [13%] vs 14 [48%], P = .012 at 30 minutes, 4 [13%] vs 12 [41%], P = .045 at 6 hours), although no significant difference was observed between group LD and group P. Postoperative pain scores, the incidence of rescue analgesic demand, and postoperative side effects were not significantly different between the groups. CONCLUSIONS: An intraoperative intravenous bolus dose of dexmedetomidine 0.5 µg·kg-1 alleviates remifentanil-induced hyperalgesia in patients undergoing thyroidectomy without a significant difference in side effects.

Effect of Dexmedetomidine on Delirium in Elderly Surgical Patients: A Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: The purpose of this meta-analysis is to assess the effect of dexmedetomidine on delirium in elderly surgical patients. DATA SOURCES: The Cochrane Library, Web of Science, PubMed, EMBASE, and Google Scholar were searched (January 1, 2000, to February 4, 2020) for randomized controlled trials (RCTs). STUDY SELECTION AND DATA EXTRACTION: RCTs without language restrictions were included if delirium incidence was assessed in elderly surgical patients receiving dexmedetomidine. Intervention and basic information were extracted. DATA SYNTHESIS: 21 studies were included. Dexmedetomidine reduced delirium occurrence (risk ratio [RR] = 0.55; 95% CI = 0.45 to 0.67) in elderly surgical patients with sufficient evidence from trial sequential analysis. Dexmedetomidine did not prevent delirium incidence for cardiac surgery (RR = 0.71; 95% CI = 0.44 to 1.15) with insufficient evidence. Dexmedetomidine decreased mortality incidence (RR = 0.47; 95% CI = 0.25 to 0.89), shortened the length of intensive care unit (ICU; standard mean difference [SMD] = -0.46) and hospital stays (SMD = -0.41), and increased bradycardia incidence (RR = 1.60). RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This review revealed that dexmedetomidine could reduce delirium incidence for elderly noncardiac surgical patients, and the effect of dexmedetomidine on delirium for elderly cardiac surgical patients needs further studies to guide clinicians. CONCLUSION: Dexmedetomidine reduced delirium incidence in elderly surgical patients. The efficacy of dexmedetomidine on delirium for elderly cardiac surgical patients warrants further studies. Furthermore, dexmedetomidine was associated with an increased bradycardia incidence, shorter length of ICU/hospital stays, and a lower incidence of mortality.

Efficacy and safety of guanfacine extended-release in Japanese adults with attention-deficit/hyperactivity disorder: Exploratory post hoc subgroup analyses of a randomized, double-blind, placebo-controlled study.

AIM: Previously, we reported on the efficacy and safety of guanfacine extended-release (GXR) in Japanese adults with attention-deficit/hyperactivity disorder (ADHD) from a phase 3, double-blind, placebo-controlled, randomized trial. In this exploratory post hoc analysis, we assessed the efficacy and/or safety of GXR in the following subgroups: ADHD-combined (ADHD-C) and ADHD-predominantly inattentive (ADHD-I) subtypes, age (≥31, <31 years), sex (male, female), and body weight (≥50, <50 kg). METHODS: The primary efficacy endpoint was change from baseline in the Japanese version of the investigator-rated ADHD-Rating Scale-IV (ADHD-RS-IV) with adult prompts (total scores) at week 10. RESULTS: The efficacy analysis population included 200 patients (GXR, 100; placebo, 100). ADHD-RS-IV total score effect sizes (GXR vs placebo) were similar across all subgroups (total population: 0.52, ADHD-C: 0.51, ADHD-I: 0.52, ≥31 years: 0.61, <31 years: 0.47, male: 0.50, female: 0.57). There were no major differences in the incidence/types of treatment-emergent adverse events (TEAEs) across the subgroups. The incidence of significant TEAEs (34.3%, 10.6%) and TEAEs leading to discontinuation (34.3%, 12.1%) were approximately three times higher in females than males, respectively. The incidence of TEAEs in patients weighing <50 kg and ≥50 kg was 100% and 73.6% during dose optimization and 40% and 24.4% during the maintenance period, respectively. CONCLUSION: Findings from this post hoc analysis in adults with ADHD support the efficacy and safety of GXR regardless of ADHD subtype, age, or sex and suggest that careful monitoring for TEAEs and GXR dose optimization is considered for all patients, as needed.

Brimonidine-associated uveitis - a descriptive case series.

BACKGROUND: Anterior uveitis secondary to topical brimonidine administration is rare and not well-defined. In glaucoma patients using brimonidine, one must consider this phenomenon to avoid mis-diagnosis and over-treatment with topical steroids which in turn may increase intraocular pressure (IOP). This is the largest case series including the longest patient follow-up in the current literature. METHODS: Sixteen patients (26 eyes) with consultant diagnosed brimonidine-associated anterior uveitis in a tertiary referral glaucoma clinic presenting between 2015 and 2019 were included in this retrospective case series. Clinical records were taken for descriptive analysis. Main outcome measures were the key clinical features, and disease course (therapy, IOP control, patient outcome). RESULTS: Key features were conjunctival ciliary injection and mutton fat keratic precipitation in all eyes. The findings were bilateral in 10 patients. Time between initiation of brimonidine treatment and presentation was 1 week to 49 months. Glaucoma sub-types were mostly pseudo-exfoliative and primary open angle glaucoma. Brimonidine treatment was stopped immediately. Additionally, topical corticosteroids were prescribed in 18 eyes and tapered down during the following 4 weeks. Thirteen eyes did not need surgical or laser treatment (median follow-up time 15 months). No patient showed recurrence of inflammation after cessation of brimonidine. CONCLUSIONS: This type of anterior uveitis is an uncommon but important manifestation which should always be considered in glaucoma patients on brimonidine treatment. Although treatable at its root cause, problems may persist, especially with respect to IOP control. The latter may necessitate glaucoma surgery after the resolved episode of the uveitis.

New directions in the treatment of opioid withdrawal.

The treatment of opioid withdrawal is an important area of clinical concern when treating patients with chronic, non-cancer pain, patients with active opioid use disorder, and patients receiving medication for opioid use disorder. Current standards of care for medically supervised withdrawal include treatment with µ-opioid receptor agonists, (eg, methadone), partial agonists (eg, buprenorphine), and α2-adrenergic receptor agonists (eg, clonidine and lofexidine). Newer agents likewise exploit these pharmacological mechanisms, including tramadol (µ-opioid receptor agonism) and tizanidine (α2 agonism). Areas for future research include managing withdrawal in the context of stabilising patients with opioid use disorder to extended-release naltrexone, transitioning patients with opioid use disorder from methadone to buprenorphine, and tapering opioids in patients with chronic, non-cancer pain.

Clonidine Compounding Error: Bradycardia and Sedation in a Pediatric Patient.

BACKGROUND: Clonidine is a centrally-acting α-2 agonist used in the treatment of hypertension and attention-deficit/hyperactivity disorder, among other off-label uses. In overdose, it can cause sedation, bradycardia, and hypotension. Clonidine can be compounded as a liquid formula for patients who are unable to take pills, however, this can add to the risk of dosing errors. CASE REPORT: A 12-year-old boy diagnosed with autism, prescribed buspirone and clonidine, presented to the emergency department for altered mental status. His examination revealed generalized sedation, bradycardia (heart rate 30-40 beats/min), and hypotension (blood pressure 82/48 mm Hg). Resuscitation included i.v. crystalloids and multiple doses of atropine. Over the next 24 h, his vital signs and mental status normalized. He displayed no infectious symptoms or focal neurologic deficits. His parents noted that his medications had been refilled recently at the compounding pharmacy; because he was unable to take pills, his medications were in liquid formulation. Because his signs and symptoms were suspicious for a central α-2 agonist overdose, his clonidine preparation was sent to a reference laboratory for analysis. This analysis revealed the concentration was approximately eight times higher than indicated on its label. WHY SHOULD AND EMERGENCY PHYSICIAN BE AWARE OF THIS?: Compounding pharmacy errors can be a source of toxicity, even if there is no known history of an overdose. Recognizing the toxidrome of sedation, respiratory depression, bradycardia, hypotension, and miosis will lead to appropriate treatment of the patient and should prompt an investigation of the medication error to prevent further harm.