Comparison of epidural butorphanol plus clonidine with butorphanol alone for postoperative pain relief.
BACKGROUND
Epidural butorphanol has been shown to produce effective analgesia with less side effects than that of morphine but relatively short duration. Clonidine, an alpha 2-adrenergic agonist, has been reported to provide [corrected] pain relief by epidural administration. Furthermore, epidural clonidine has been shown to potentiate the analgesic effect of epidural morphine. The present study was undertaken to evaluate the analgesic and side effects of epidural administration (Ep) of butorphanol and clonidine.


METHODS
After giving their consents, 60 adult patients scheduled for abdominal surgeries were enrolled in this study. Prior to anesthesia induction, indwelling lumbar epidural catheters were placed in all patients who then received general anesthesia with inhalation anesthetic without narcotic analgesics. In the postoperative period, when the patients first complained of pain, they were divided into 2 equal groups of 30 patients each in a randomized and double blinded fashion with Group I receiving Ep butorphanol 0.5 mg and Group II receiving Ep butorphanol 0.5 mg plus clonidine 75 micrograms. All patients were observed for pain relief, sedation, vital signs, arterial blood gas studies and adverse effects for 12 h.


RESULTS
Onset of pain relief with epidural butorphanol began at 5 min and peaked at 20-30 min with a duration of action lasting 4-6 h. The combination of butorphanol and clonidine had numerically superior pain relief than that of butorphanol for the first 30 min but it did not attain statistical significant difference. The duration of action with the combination group was similar to that of butorphanol alone. Incidence of adverse effects were similar in both groups except that hypotension and more pronounced sedation were observed in Group II.


CONCLUSIONS
Our study showed that the addition of clonidine to epidural butorphanol did not enhance its analgesic effect in any significant manner nor did it reduce the adverse effects. This combination does not seem to offer any advantage for clinical use.
Tan
P H
PH
Department of Anesthesiology, Military 802 General Hospital, Kaohsiung, Taiwan, R.O.C.
Chou
A K
AK
Perng
J S
JS
Chung
H C
HC
Lee
C C
CC
Mok
M S
MS
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage*; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D002077:Butorphanol / Q000008:administration & dosage / Q000627:therapeutic use*; D003000:Clonidine / Q000008:administration & dosage*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy*; D012119:Respiration / Q000187:drug effects
D000316:Adrenergic alpha-Agonists; D000701:Analgesics, Opioid; D003000:Clonidine; D002077:Butorphanol