Chronic low back pain is a phrase used to describe pain that has persisted for 6 months or more, well beyond what is considered typical healing time for common low back injuries that will heal on their own. A recent study suggests that taking 60mg of Cymbalta (duloxetine) once daily may significantly reduce the effects of chronic low back pain.
Duloxetine functions as a serotonin and norepinephrine reuptake inhibitor and is often used for the treatment of depression and anxiety disorders. When present in the brain and spinal cord, serotonin and norepinephrine act to stabilize mood and regulate the perception of pain.
The 12-week double-blind, placebo-controlled study examined the efficacy of 60 mg of duloxetine once daily on the reduction of pain severity in patients suffering from chronic low back pain. Results were based on a Brief Pain Inventory (BPI) rating. Study results were presented at the annual meeting of the American Academy of Pain Medicine (AAPM) on February 3, 2010.
All participants were adults with non-neuropathic chronic low back pain and a pain intensity rating greater than or equal to 4 on the 11-point BPI scale. Of 401 participants, 198 were given 60mg of duloxetine once daily while 203 were given a placebo.
At the conclusion of the study, patients treated with duloxetine experienced a reduction in pain on the BPI scale that was statistically greater than the pain reduction experienced by the placebo group. A 30% pain reduction is typically considered clinically significant by physicians (2001. Pain (94):149-158)
A total of 41 patients discontinued the study due to adverse side effects. The most commonly reported adverse effects were nausea, headache, dry mouth, constipation and dizziness. All are consistent with effects reported in previous duloxetine studies.
Cymbalta is approved for use in adults for the treatment of major depressive disorder, generalized anxiety disorder, management of peripheral neuropathic pain, and management of fibromyalgia.
Some previous Cymbalta studies have also shown pain decreases, but with a tapering off of pain reduction differences between the drug and placebo. The question is how long the difference will last and how that timeframe of pain reduction should be handled as part of an ongoing treatment plan for managing chronic low back pain.
Study reference: Skljarevski, et al. "Effect of Duloxetine 60 mg Once-daily Versus Placebo in Patients With Chronic Low Back Pain: A 12-week, Randomized, Double-blind Trial." Presented at 2010 American Academy of Pain Medicine Annual Meeting, Feb. 3, 2010.