Short-Term Pain Relief Versus Long-Term Uncertainty in Bisphosphonate Therapy for CRPS

Article Impact Level: HIGH
Data Quality: STRONG
Summary of  Annals of Internal Medicine https://doi.org/10.7326/ANNALS-25-03693 
Dr. Michael C. Ferraro  et al.

Points

Researchers analyzed eleven randomized controlled trials involving 754 adults to evaluate the efficacy of five different bisphosphonates for treating complex regional pain syndrome.
The meta-analysis found that bisphosphonate treatment was associated with a reduction in pain intensity during the short term of four weeks to three months.
Data regarding immediate, medium, and long-term outcomes showed little to no significant difference in pain intensity between the treatment groups and placebo controls.
Patients receiving bisphosphonates demonstrated a probable increase in the risk for adverse events with a calculated risk ratio of 1.1 compared to placebo.
The study concludes that while short-term relief is possible, high heterogeneity and safety concerns suggest clinicians must carefully evaluate patient suitability for this therapy.

Summary

This systematic review and meta-analysis evaluated the efficacy and safety of bisphosphonates for adults with complex regional pain syndrome (CRPS). Analyzing 11 randomized controlled trials involving 754 participants, predominantly with CRPS type I, researchers assessed five bisphosphonate formulations (alendronate, clodronate, neridronate, pamidronate, and zoledronate) administered via oral or intravenous routes. Primary outcomes focused on pain intensity and adverse events, with data synthesized using random-effects models to determine clinical utility in this challenging chronic condition.

Results indicated that bisphosphonates reduced pain intensity in the short term (>4 weeks to 3 months), showing a mean difference (MD) of -10.0 (95% CI, -18.9 to -1.1) on a 0-to-100 scale. However, efficacy was not established across other timeframes. Immediate-term effects (≤4 weeks) showed no significant difference (MD -9.1 [95% CI, -19.2 to 1.1]), and medium-term assessments (>3 to 6 months) similarly found no benefit (MD 8.0 [95% CI, -15.4 to 31.4]). Evidence regarding long-term efficacy (>6 months) was highly uncertain (MD -2.5 [95% CI, -19.6 to 14.6]), highlighting a lack of sustained therapeutic impact.

Regarding safety, bisphosphonates were associated with a probable increase in the risk for adverse events, with a risk ratio of 1.1 (95% CI, 1.0 to 1.2), primarily involving joint and muscle symptoms. The authors noted high heterogeneity among the included studies and limited data on U.S.-approved formulations. Consequently, while bisphosphonates may offer transient symptomatic relief, the lack of long-term efficacy and the increased risk of adverse events necessitate a careful risk-benefit assessment by clinicians.

Link to the article: https://www.acpjournals.org/doi/10.7326/ANNALS-25-03693

References

Ferraro, M. C., O’Connell, N. E., Goebel, A., Hill, R., Curtis, F., Wilkinson, J., Center, J. R., Gustin, S. M., Cashin, A. G., & McAuley, J. H. (2025). Efficacy and safety of bisphosphonates for complex regional pain syndrome: A systematic review and meta-analysis. Annals of Internal Medicine, ANNALS-25-03693. https://doi.org/10.7326/ANNALS-25-03693