Low Dose Naltrexone Therapy for Complex Regional Pain Syndrome

Complex Regional Pain Syndrome (CRPS) is a rare and often debilitating chronic pain condition whereby individuals may experience extreme sensitivity, discoloration, and swelling of the affected area -- along with numerous other painful symptoms. There are currently a limited number of treatment options available to those suffering with the condition, with various treatments including nerve blocks, neuropathic medications, and desensitization physical therapy modules. There is budding interesting in the role naltrexone, an opiate antagonist, may play in the pain management of CRPS when prescribed in very low doses. This study aims to collect preliminary data on pain scores, symptom severity, and side-effects in patients with Complex Regional Pain Syndrome randomized to receive low dose naltrexone or placebo capsules. Enrollment of 40 patients total will occur over two years from study start to study end. Each patient will be randomized to receive placebo capsules or active low dose naltrexone capsules, with both the patient and treating clinician blind to the randomization. Each patient will be actively enrolled in the study for six months and will take the medication daily at the instructed dose for the respective duration of time. Following the initial visit and study enrollment, the investigators are asking each patient to return for three (3) in-person follow-up office visits. These office visits will occur 1 month after the patient starts the medication, 3 months afterwards, and 6 months afterwards. The final 6-month office visit will mark the conclusion of the patient's active participation in the study.

NCT Number	NCT06306157
Lead Sponsor	Hospital for Special Surgery, New York
Conditions	Complex Regional Pain Syndrome, Chronic Pain, Causalgia, Complex Regional Pain Syndrome Type I, Complex Regional Pain Syndrome Type II
Enrollment	40 participants
Start Date	2024-01-02
Primary Completion	2026-08 (estimated)
Study Completion	2026-11 (estimated)
Updated on ClinicalTrials.gov	2026-06-18