Efficacy of amitriptyline for relief of pain in spinal cord injury: results of a randomized controlled trial

Abstract

Chronic pain in persons with spinal cord injury (SCI) is a difficult problem for which there is no simple method of treatment. Few randomized controlled trials of medications for pain in persons with SCI have been conducted. This study was designed to determine whether amitriptyline, a tricyclic antidepressant, is efficacious in relieving chronic pain and improving pain-related physical and psychosocial dysfunction in persons with SCI. Eighty-four participants with SCI and chronic pain were randomized to a 6-week trial of amitriptyline or an active placebo, benztropine mesylate. All pre- and post-treatment assessments were conducted by evaluators blind to the allocation. Regression analyses were conducted to examine whether there was a medication group effect on the primary (average pain intensity) and secondary outcome measures. No significant differences were found between the groups in pain intensity or pain-related disability post-treatment, in either intent-to-treat analyses or analyses of study completers. These findings do not support the use of amitriptyline in the treatment of chronic pain in this population, but we cannot rule out the possibility that certain subgroups may benefit.