Intravenous (i.v.)
bisphosphonates relieve
pain in conditions such as
Paget's disease of bone, metastatic
bone disease, and
multiple myeloma. Based on positive findings from a prior case series, we conducted a randomized placebo-controlled study to assess the
analgesic effect of i.v.
pamidronate in subjects with chronic
low back pain (CLBP) and evidence of degenerative disease of the spine. Four groups of 11 subjects (7 active, 4 placebo) were enrolled at escalating dose levels of 30, 60, 90, and 180 mg
pamidronate (the latter administered as two 90 mg infusions). Primary outcomes were safety and change from baseline in average daily
pain scores, recorded at 1, 2, 3, and 6 months postinfusion using electronic diaries. Secondary outcomes included responder rate, daily worst
pain, and
pain-related interference with daily function. There were no
pamidronate-related serious adverse events or other significant safety findings. A statistically significant overall treatment difference in
pain scores was observed, with clinically meaningful effects persisting for 6 months in the 180 mg
pamidronate group. Least squares mean changes in daily average
pain score were -1.39 (SE=0.43) for placebo, and -1.53 (0.71), -1.26 (0.81), -1.42 (0.65), and -4.13 (0.65) for
pamidronate 30, 60, 90, and 180 mg, respectively (P=0.012 for
pamidronate 180 mg vs placebo). The proportion of responders, changes in worst
pain, and
pain interference with daily function were also significantly improved for
pamidronate 180 mg compared with placebo. In conclusion, i.v.
pamidronate, administered as two 90 mg infusions, decreased
pain intensity for 6 months in subjects with CLBP.