首页   按字顺浏览 期刊浏览 卷期浏览 Intrathecal ClonidineAnalgesia and Effect on Opiate Withdrawal in the Rat
Intrathecal ClonidineAnalgesia and Effect on Opiate Withdrawal in the Rat

 

作者: Brian Milne,   Frank Cervenko,   Khem Jhamandas,   Maaja Sutak,  

 

期刊: Anesthesiology  (OVID Available online 1985)
卷期: Volume 62, issue 1  

页码: 34-38

 

ISSN:0003-3022

 

年代: 1985

 

出版商: OVID

 

关键词: Analgesics: clonidine;morphine;tolerance;Anesthetic techniques: spinal;Antagonists, narcotic: naloxone;Spinal cord: receptors

 

数据来源: OVID

 

摘要:

Clonidine, an α2, adrenergic agonist, has analgesic properties and recently has been used to suppress opiate withdrawal. These two properties theoretically make it a suitable analgesic substitute in patients tolerant to opioids. The objectives of this study were to see if intrathecal clonidine is analgesic and whether it can modify morphine withdrawal at the spinal level. Rats chronically implanted with catheters in the lumbar subarachnoid space were utilized. In analgesia experiments, intrathecal clonidine produced analgesia with the peak effect in the paw-lick test occurring at 200 nM, and in the tail-flick test analgesia was apparent at 100 nM and peaked at 400 nM (in 10 μL Ringer's lactate). In dependency experiments, animals dependent on morphine (300 mg · kg−1) received intrathecal clonidine 25, 50, 200 nM in 10 μ1 Ringer's lactate 72 h after morphine. Following this, a naloxone challenge, 3 mg · kg−1was administered and withdrawal assessed.Clonidine-treated animals showed significant weight loss and decrease in temperature, and those treated with high doses showed marked hypothermia and hind-limb flaccidity. Intrathecal clonidine prevented the hyperalgesia associated with opiate withdrawal but did not affect the occurrence of the majority of behavioral signs (e.g., piloerection, irritability) associated with morphine withdrawal. Intrathecal clonidine prevented the naloxone-induced increase in blood pressure during withdrawal and in animals not treated with morphine-produced hypotension. Thus, intrathecal clonidine is analgesic, and part of the antiwithdrawal action of clonidine may be exerted at the spinal level.

 

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