Low-Dose Antidepressant Could Treat Low Back Pain

Chronic low back pain could be relieved with low doses of the tricyclic antidepressant amitriptyline, according to the results of a recent study.

Although antidepressants are commonly used to treat chronic low back pain and are recommended for this use in international guidelines, no evidence is available for their efficacy, according to the study authors.

For this reason, they conducted a double-blind, randomized clinical trial of 146 adults with chronic, nonspecific low back pain randomly assigned to receive either low-dose amitriptyline (25 mg/d) or benztropine mesylate (1mg/d) for 6 months.

The primary outcome of pain intensity was measured at 3 and 6 months with the visual analog scale and Descriptor Differential Scale. Secondary outcomes included disability and work absence.

Of the 146 participants, 118 completed the 6-month follow-up. The researchers found that treatment with low-dose amitriptyline was not associated with greater pain reduction than benztropine mesylate at 3 or 6 months, but they did observe a statistically significant improvement in disability in the low-dose amitriptyline group at 3 months.

“This trial suggests that amitriptyline may be an effective treatment for chronic low back pain. There were no significant improvements in outcomes at 6 months, but there was a reduction in disability at 3 months, an improvement in pain intensity that was nonsignificant at 6 months, and minimal adverse events reported with a low-dose, modest sample size and active comparator. Although large-scale clinical trials that include dose escalation are needed, it may be worth considering low-dose amitriptyline if the only alternative is an opioid.”

—Michael Potts

Reference:

Urquhart DM, Wluka AE, Tulder M, et al. Efficacy of low-dose amitriptyline for chronic low back pain [Published online October 1, 2018]. JAMA Intern Med. doi:10.1001/jamainternmed.2018.4222