Efficacy and safety of neridronate in paediatric type I complex regional pain syndrome: a multicentre experience

Objectives: Evidence regarding the efficacy of neridronate in the treatment of complex regional pain syndrome type I (CRPS I) is increasing, however, very little data are available in paediatric age. Our aim was to analyse the safety and the efficacy of neridronate in a case series of children with CRPS I, according to the Budapest criteria, who did not respond to previous pharmacological and physical therapy. Methods: We collected data of children affected by CRPS I from three paediatric rheumatology centres who received neridronate. Efficacy was evaluated by changes in pain intensity, vasomotor changes, physical function, need for pain medications and MRI findings. Adverse effects were also documented. Results: Five children (3 females and 2 males, mean age 10.4 years, range 7-13 years) who received neridronate (4 intravenous, 1 intramuscular) were included. All patients had failed previous medical treatments (NSAIDs in 4, local steroids in 2, gabapentin, vitamin D and calcium supplementation in 1) and non-medical therapies (physiotherapy in 4, magnetotherapy in 2, laser in 1). Four out of five patients reported a significant improvement in pain (average VAS pre-treatment 9.6, post-treatment 2.6), recovery of physical function, and a reduced need for pain medications. Before treatment, all patients underwent MRI which revealed bone oedema that disappeared in the three of them after treatment. Neridronate was well-tolerated as only one patient experienced mild flu-like symptoms. Conclusions: Our data suggest that in children as in adults with CRPS I, neridronate may represent an effective and safe treatment option, particularly in those who do not respond to other pain treatments.