Antidepressant value in back pain unclear

Low-dose amitriptyline does not have clear benefits for patients with chronic low-back pain that has no specific cause, according to a randomised clinical trial by Monash University researchers.

Despite the lack of evidence that antidepressants are more effective than placebo for low-back pain, seven of 14 national and international guidelines recommend their use in this setting.

Researchers from Monash University in Melbourne investigated whether low-dose amitriptyline (25mg per day) was effective in reducing pain, disability and work absence and hindrance over six months in 146 patients with chronic, nonspecific low-back pain.

They compared the drug with benztropine, which mimics the adverse events of amitriptyline but has no known effect on chronic pain.

At baseline, participants had a mean pain score of 41.6/100 and a mean disability score of 7.9/23.

One-quarter of patients reported