TY - JOUR
T1 - Morphine responses and experimental pain
T2 - Sex differences in side effects and cardiovascular responses but not analgesia
AU - Fillingim, Roger B.
AU - Ness, Timothy J.
AU - Glover, Toni L.
AU - Campbell, Claudia M.
AU - Hastie, Barbara A.
AU - Price, Donald D.
AU - Staud, Roland
N1 - Funding Information:
Supported by NIH grant NS41670 and General Clinical Research Center Grant RR00082.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005/2
Y1 - 2005/2
N2 - Sex differences in analgesic responses to μ opioid agonists have been reported, although the direction of these differences varies across studies. To further characterize sex differences in responses to μ opioids, the analgesic effects of intravenous morphine (0.08 mg/kg) were determined in healthy women (n = 61) and men (n = 39) by using 3 experimental pain models, heat pain, pressure pain, and ischemic pain. Each pain procedure was conducted before and after double-blind administration of both morphine and saline, which occurred on separate days in counterbalanced order. Although morphine produced significant analgesic effects for all pain stimuli, no significant sex differences in morphine analgesia emerged. However, morphine attenuated cardiovascular reactivity to the ischemic pain task in men but not women, and women reported significantly more drug-related adverse effects than men. These findings are in contrast with some recent clinical and experimental results suggesting more robust analgesic response to μ opioids among women compared to men, although the data indicate that sex differences in non-analgesic effects of morphine were present. These results suggest that sex differences in responses to morphine might depend on the pain model and/or drug dose as well as the specific end point assessed.
AB - Sex differences in analgesic responses to μ opioid agonists have been reported, although the direction of these differences varies across studies. To further characterize sex differences in responses to μ opioids, the analgesic effects of intravenous morphine (0.08 mg/kg) were determined in healthy women (n = 61) and men (n = 39) by using 3 experimental pain models, heat pain, pressure pain, and ischemic pain. Each pain procedure was conducted before and after double-blind administration of both morphine and saline, which occurred on separate days in counterbalanced order. Although morphine produced significant analgesic effects for all pain stimuli, no significant sex differences in morphine analgesia emerged. However, morphine attenuated cardiovascular reactivity to the ischemic pain task in men but not women, and women reported significantly more drug-related adverse effects than men. These findings are in contrast with some recent clinical and experimental results suggesting more robust analgesic response to μ opioids among women compared to men, although the data indicate that sex differences in non-analgesic effects of morphine were present. These results suggest that sex differences in responses to morphine might depend on the pain model and/or drug dose as well as the specific end point assessed.
UR - http://www.scopus.com/inward/record.url?scp=13444282299&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=13444282299&partnerID=8YFLogxK
U2 - 10.1016/j.jpain.2004.11.005
DO - 10.1016/j.jpain.2004.11.005
M3 - Article
C2 - 15694878
AN - SCOPUS:13444282299
VL - 6
SP - 116
EP - 124
JO - Journal of Pain
JF - Journal of Pain
SN - 1526-5900
IS - 2
ER -