Randomized double-blind controlled study of bedtime low-dose amitriptyline in chronic neck pain.

Abstract

Amitriptyline has well-established efficacy in several chronic pain conditions. While optimal treatment for chronic neck pain (CNP) remains controversial, amitriptyline was not tested for CNP. We evaluated the effect of bedtime amitriptyline in the management of CNP. A total of 220 patients suffering from idiopathic CNP were randomized to receive either placebo pill (n=108) or 5mg of amitriptyline (n=112) at bedtime for 2months. Primary outcome measure was visual analog scale (VAS) for pain. Secondary outcome measures were neck pain disability index (NPDI), Bergen Insomnia Score (BIS) and Hospital Anxiety and Depression Scale (HAD), measured before and at the end of 2months of treatment, with the percentage of patient satisfaction measured at the end of follow-up only. Eight of 112 patients (7.14%) in the amitriptyline group withdrew from the study because of intolerance. Amitriptyline group showed significantly lower VAS scores than placebo group (3.34±1.45 vs. 6.12±0.92; p<0.0001), which corresponds to a 53.06±20.29% of improvement from baseline pain as compared to 14.41±11.05%, respectively (p<0.0001). Similar significant improvements were observed with lesser extents for secondary outcome measures: NPDI, BIS, HAD-A, HAD-D and percentage of patient satisfaction. Low-dose amitriptyline is effective for the management of idiopathic CNP with few side effects and high patients' satisfaction. This randomized controlled trial is the first to show the effectiveness and tolerance of a medication, low-dose amitriptyline, in managing idiopathic chronic neck pain and its related comorbidities. The optimal treatment of this condition was still controversial in the literature. It extends the indication of low-dose amitriptyline to another chronic pain condition.