[What is the place of diphosphonates in the treatment of complex regional pain syndrome I?].

Objectives: To evaluate the efficacy of biphosphonates (BPs) in complex regional pain syndrome I or reflex sympathetic dystrophy and to specify their place in this chronic painful syndrome.
Methods: A literature review of Medline and Embase with use of a combination of 3 key words: biphosphonates therapy, reflex sympathetic dystrophy, complex regional pain syndrome I, controlled study. Each article was classified by 2 independent reviewers according to Aguilar's method into high, middle or low quality.
Results: Three second-generation BPs were tested in the treatment of reflex sympathetic dystrophy: pamidronate, alendronate and clodronate. Many open studies investigated pamidronate, but only 2 were randomised and controlled: a low-quality trial comparing pamidronate with placebo and a middle-quality trial comparing pamidronate with calcitonine. Two high-quality trials were performed, 1 with alendronate and 1 with clodronate. Middle-quality trial and high-quality trials reported positive effects on pain with BPs in recent reflex sympathetic dystrophy (disease duration less than eight months). Side effects (fever, asymptomatic hypocalcemia) were observed frequently but disappeared quickly.
Conclusion: BPs can be used in recent reflex sympathetic dystrophy when calcitonin is inefficient or when calcitonin injections are not well tolerated.