The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
Gilles L Fraser - One of the best experts on this subject based on the ideXlab platform.
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transition from dexmedetomidine to enteral Clonidine for icu sedation an observational pilot study
Pharmacotherapy, 2015Co-Authors: David R Gagnon, Richard R Riker, Elizabeth Glisic, Andrew Kelner, Hilary M Perrey, Gilles L FraserAbstract:Introduction Enteral Clonidine represents a potentially less costly alternative to dexmedetomidine for sedation in intensive care unit (ICU) patients. This study describes our practice of transitioning selected adult ICU patients from dexmedetomidine to Clonidine with a focus on efficacy, safety, and drug acquisition costs. Methods We conducted a single-center prospective observational pilot study from January through March 2014. Consecutive patients 18 years and older treated with dexmedetomidine and transitioned to Clonidine were followed. The transition was assessed in five phases: dexmedetomidine maintenance, transition, Clonidine maintenance, Clonidine taper, and post Clonidine. Efficacy data included any occurrence of significant pain, excessive agitation or oversedation, delirium, and need for ancillary psychoactive medications. Safety data included any occurrence of bradycardia, hypotension, new second- or third-degree atrioventricular node blockade, and Clonidine withdrawal syndrome. Drug acquisition cost avoidances were estimated using average wholesale price. Results Twenty patients were evaluated. Fifteen (75%) were successfully transitioned from dexmedetomidine within 48 hours of starting Clonidine. The initial and maintenance Clonidine regimens were 0.3 mg every 6 hours. Clonidine was the sole α2A-receptor agonist administered for 45 hours while in the ICU and for 54 hours outside the ICU. Fentanyl requirements were lower when Clonidine was administered as the sole α2A-receptor agonist as compared to dexmedetomidine alone (387 vs. 891 μg/day, p = 0.03). Otherwise, there were no statistically significant differences in efficacy data during the dexmedetomidine and Clonidine maintenance phases. No statistically significant differences in safety data were observed. Clonidine withdrawal syndrome criteria were met in one patient. The potential drug acquisition cost avoidance was $819–$2338 per patient during the 3-month study. Conclusions Transitioning from dexmedetomidine to Clonidine may be an efficacious, safe, and less costly method of maintaining α2A-receptor agonist therapy in critically ill adults; these results warrant confirmation in expanded studies.
Claude Ecoffey - One of the best experts on this subject based on the ideXlab platform.
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Ventilatory effects of premedication with Clonidine.
Anesthesia and analgesia, 1991Co-Authors: Dan Benhamou, Yves Veillette, P. Narchi, Claude EcoffeyAbstract:Clonidine has been proposed as a premedication before surgery because of its beneficial effects on hemodynamics, especially in patients with a high cardiovascular risk. However, reports on the effects of Clonidine on ventilation are conflicting. Accordingly, eight fasting ASA physical status I volunteers received in a double-blind randomized order 300 micrograms of oral Clonidine, the effects of which were compared with placebo given in a crossover design. Hypotension, bradycardia, and sedation were significantly more profound and of longer duration after Clonidine. Clonidine did not decrease minute ventilation more than the placebo, and separate analysis of tidal volume and respiratory rate changes also showed the absence of a significant difference between the two groups. However, Clonidine produced episodes of obstructive pattern associated with moderate decreases in oxygen saturation, which were not observed with placebo. We conclude that the potential detrimental effects of these obstructive airway patterns of Clonidine should be taken into account when prescribing this drug for premedication.
Naser Abbasi - One of the best experts on this subject based on the ideXlab platform.
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the inhibitory effect of hypericum perforatum extract on morphine withdrawal syndrome in rat and comparison with Clonidine
Phytotherapy Research, 2009Co-Authors: Amir Feily, Naser AbbasiAbstract:The effects of Hypericum perforatum (St John's wort) on morphine withdrawal syndrome and comparison with Clonidine have been investigated in morphine-dependent rats. Adult male Wistar rats were subjects. The frequencies of withdrawal behavioral signs (rearing, teeth chattering and jumping) induced by naloxone challenge were demonstrated in morphine dependent rats receiving Hypericum perforatum extract (HPE), saline or Clonidine. The withdrawal behavioral manifestations in rats were inhibited significantly by chronic co-administration of Hypericum perforatum extract or Clonidine with morphine. This study showed that Clonidine was more effective than HPE at a dose of 0.4 mL/200 g and there was no significant statistical difference between the mean frequency of withdrawal signs of HPE at a dose of 0.8 mL/200 g compared with Clonidine (0.2 mg/kg i.p.) but at a dose of 1.2 mL/200 g of HPE was significantly stronger than Clonidine in attenuation of the morphine withdrawal syndrome. The findings suggest that HPE is capable of reducing the symptoms of opiate withdrawal and its effectiveness may be equivalent to Clonidine in reducing the opiate withdrawal syndrome and may have human therapeutic potential. Copyright © 2009 John Wiley & Sons, Ltd.
Z Wiesenfeldhallin - One of the best experts on this subject based on the ideXlab platform.
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the depressive effect of intrathecal Clonidine on the spinal flexor reflex is enhanced after sciatic nerve section in rats
Pain, 1992Co-Authors: Xiao-jun Xu, Malcolm J C Puke, Z WiesenfeldhallinAbstract:Abstract The effect of intrathecal (i.t.) α 2 -adrenoceptor agonist, Clonidine, on the spinal nociceptive flexor reflex was studied in decerebrate, spinalized, unanesthetized rats with intact sciatic nerves or in rats in which the sciatic nerve had been ipsilaterally sectioned. In rats with intact nerves i.t. Clonidine caused a dose-dependent biphasic effect on flexor reflex excitability. At low dose (10 ng) the effect of Clonidine was purely facilitatory, whereas with 50–100 ng Clonidine the initial facilitation was often followed by reflex depression. Long-lasting, strong reflex depression was observed after i.t. injection of high doses of Clonidine (1 and 10 μg). Four to 18 days after sciatic nerve section, the depressive effect of Clonidine on the flexor reflex was dramatically enhanced. Depression was frequently observed already with doses of 5 and 10 ng, and maximal depression was reached at 100 ng and 1 μg in axotomized rats. The facilitatory effect of low doses of Clonidine on the reflex was also observed, although somewhat less frequently than in normals. The depressive effect of Clonidine on the flexor reflex was reversed by the selective α 2 -receptor antagonist, atipamezole (20 μg i.t.), in rats with both intact and sectioned sciatic nerves. The present results revealed an increased sensitivity and effectiveness of the depression of spinal reflex mechanisms by i.t. Clonidine after sciatic nerve section, which is opposite to the decreased sensitivity to i.t. morphine after axotomy that we observed previously. Since the flexor reflex is evoked by the activation of afferents that may be the source of neuropathic pain after nerve lesion, the results support the usefulness of i.t. Clonidine in treating pain associated with peripheral nerve injury.
Philippa Middleton - One of the best experts on this subject based on the ideXlab platform.
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Clonidine premedication for postoperative analgesia in children
Cochrane Database of Systematic Reviews, 2014Co-Authors: Paul Lambert, A M Cyna, Nicholas Knight, Philippa MiddletonAbstract:Background Postoperative pain remains a significant problem following paediatric surgery. Premedication with a suitable agent may improve its management. Clonidine is an alpha-2 adrenergic agonist which has sedative, anxiolytic and analgesic properties. It may therefore be a useful premedication for reducing postoperative pain in children. Objectives To evaluate the evidence for the effectiveness of Clonidine, when given as a premedication, in reducing postoperative pain in children less than 18 years of age. We also sought evidence of any clinically significant side effects. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 12, 2012), Ovid MEDLINE (1966 to 21 December 2012) and Ovid EMBASE (1982 to 21 December 2012), as well as reference lists of other relevant articles and online trial registers. Selection criteria We included all randomized (or quasi-randomized), controlled trials comparing Clonidine premedication to placebo, a higher dose of Clonidine, or another agent when used for surgical or other invasive procedures in children under the age of 18 years and where pain or a surrogate (principally the need for supplementary analgesia) was reported. Data collection and analysis Two authors independently performed the database search, decided on the inclusion eligibility of publications, ascertained study quality and extracted data. They then resolved any differences between their results by discussion. The data were entered into RevMan 5 for analyses and presentation. Sensitivity analyses were performed, as appropriate, to exclude studies with a high risk of bias. Main results We identified 11 trials investigating a total of 742 children in treatment arms relevant to our study question. Risks of bias in the studies were mainly low or unclear, but two studies had aspects of their methodology that had a high risk of bias. Overall, the quality of the evidence from pooled studies was low or had unclear risk of bias. Four trials compared Clonidine with a placebo or no treatment, six trials compared Clonidine with midazolam, and one trial compared Clonidine with fentanyl. There was substantial methodological heterogeneity between trials; the dose and route of Clonidine administration varied as did the patient populations, the types of surgery and the outcomes measured. It was therefore difficult to combine the outcomes of some trials for meta-analysis. When Clonidine was compared to placebo, pooling studies of low or unclear risk of bias, the need for additional analgesia was reduced when Clonidine premedication was given orally at 4 µg/kg (risk ratio (RR) 0.24, 95% confidence interval (CI) 0.11 to 0.51). Only one small trial (15 patients per arm) compared Clonidine to midazolam for the same outcome; this also found a reduction in the need for additional postoperative analgesia (RR 0.25, 95% CI 0.09 to 0.71) when Clonidine premedication was given orally at 2 or 4 µg/kg compared to oral midazolam at 0.5 mg/kg. A trial comparing oral Clonidine at 4 µg/kg with intravenous fentanyl at 3 µg/kg found no statistically significant difference in the need for rescue analgesia (RR 0.89, 95% CI 0.56 to 1.42). When Clonidine 4 µg/kg was compared to Clonidine 2 µg/kg, there was a statistically significant difference in the number of patients requiring additional analgesia, in favour of the higher dose, as reported by a single, higher-quality trial (RR 0.38, 95% CI 0.23 to 0.65). The effect of Clonidine on pain scores was hard to interpret due to differences in study methodology, the doses and route of drug administration, and the pain scale used. However, when given at a dose of 4 µg/kg, Clonidine may have reduced analgesia requirements after surgery. There were no significant side effects of Clonidine that were reported such as severe hypotension, bradycardia, or excessive sedation requiring intervention. However, several studies used atropine prophylactically with the aim of preventing such adverse effects. Authors' conclusions There were only 11 relevant trials studying 742 children having surgery where premedication with Clonidine was compared to placebo or other drug treatment. Despite heterogeneity between trials, Clonidine premedication in an adequate dosage (4 µg/kg) was likely to have a beneficial effect on postoperative pain in children. Side effects were minimal, but some of the studies used atropine prophylactically with the intention of preventing bradycardia and hypotension. Further research is required to determine under what conditions Clonidine premedication is most effective in providing postoperative pain relief in children.