A double-blind comparison between epidural morphine and epidural clonidine in patients with chronic non-cancer pain.
In a randomised double-blind study of 20 patients with chronic pain, epidural morphine 5 mg in 5 ml of saline was compared with epidural clonidine 150 micrograms in 5 ml of saline. Thirteen patients had a clinical and radiological diagnosis of arachnoiditis, 6 had low back pain and 1 had post-operative scar pain. There were 18 females and 2 males with an average age of 52 years, range 22-76 years. There was no difference found between the 2 solutions in the resultant analgesia measured by the visual analogue scale for pain, pain relief or the pain word score during the 3 h period of the study. No difference was found in the patient's mood which was also measured with the visual analogue scale. Two patients had no analgesia from either injection, 2 patients did not obtain any relief from clonidine and another 2 obtained no relief from morphine. Six patients reported that clonidine was better than morphine, 5 reported that morphine and clonidine were the same and 3 reported that morphine was better than clonidine. The duration of analgesia from the clonidine varied from 6 h to 1 month; the duration of analgesia from morphine varied from 6 to 24 h. Clonidine was associated with sedation and a fall in blood pressure of greater than 20 mm Hg in all patients, 1 patient required ephedrine to treat hypotension. Twelve patients had pruritus, 7 nausea and 2 vomiting following the morphine. Statistically there was no difference found between morphine and clonidine for short-term (3 h) analgesia in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Glynn
Chris
C
Oxford Regional Pain Relief Unit, and Pain Relief Research Unit, Abingdon Hospital, Abingdon OX14 1AG U.K. Nuffield Department of Anaesthetics, The Radcliffe Infirmary, Oxford OX2 6HE U.K.
Dawson
David
D
Sanders
Rosemary
R
D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003000:Clonidine / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000009:adverse effects; D010146:Pain / Q000188:drug therapy*
D009020:Morphine; D003000:Clonidine