Does raloxifene treatment influence back pain and disability among postmenopausal women with osteoporosis?

Clinical studies have suggested that postmenopausal women on estrogen replacement treatment are more likely to experience back pain and related disability compared to women who do not take estrogens. Raloxifene, a selective estrogen receptor modulator has estrogen-like effects on bone tissue, and antagonize the action of estrogens on endometrium and breast tissue. It is unknown if the treatment of osteoporosis with raloxifene has estrogen-like or opposite effects on back pain and functional capacity among postmenopausal women with osteoporosis. A total of 120 postmenopausal women with osteoporosis and chronic back pain were randomized to receive raloxifene 60 mg with 1,000 mg calcium, and 800 IU vitamin D daily or 1,000 mg calcium and 800 IU vitamin D daily. Pain intensity and pain-related disability were measured before treatment at 6 months and after 1 year. Repeated measures of ANOVA, did not reveal statistically significant differences over time, on pain intensity and disability scores, between groups studied. There was a trend in pain intensity changes during the follow-up period, but the differences between the groups were not statistically significant. It seems that treatment with raloxifene does not influence back pain and disability among postmenopausal women with osteoporosis. Raloxifene may have estrogenic agonist effects on nociceptive processing in the central nervous system.