I’ve had ongoing back and neck pain for years and nothing has helped it, from physical therapy to acupuncture. But recently I heard that the antidepressant duloxetine might be effective for chronic pain. Is that true?
When exercise and over-the-counter medications don’t provide sufficient relief for chronic musculoskeletal pain, and if you’ve also tried lifestyle changes and techniques such as acupuncture, meditation, and cognitive behavioral therapy, duloxetine (brand name Cymbalta) might be worth considering. You take this drug—usually prescribed in dosages of 30 or 60 milligrams—regularly and every day, not on an as-needed basis as you would do with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.
How well duloxetine might work for you depends on several factors, including the intensity and type of pain you have, as well as how long you’ve been experiencing it. Neck pain, for instance, is often due mostly to the wear-and-tear osteoarthritic changes that occur with aging. But when your pain is caused by inflammation of the nerves themselves—which can occur also in osteoarthritis as bony changes impinge on nerves, as well as in other conditions—it is classified as neuropathic. Neuropathic pain can cause considerable distress, is more difficult to treat than garden-variety pain, and typically does not respond well to ordinary pain medication, such as NSAIDs (or even narcotics). Duloxetine can be used to treat both neuropathic and non-neuropathic types of pain, but there’s currently no easy path to confidently predict whether or how much a person will benefit from taking it.
Duloxetine is not a new drug, and over the years it has been approved for several conditions. The FDA first approved it in 2004 for depression. Shortly after that same year, it was cleared for use with neuropathic pain that can accompany diabetes. In 2007, the FDA green-lighted it to prevent relapse of major depressive disorder, and soon after to treat fibromyalgia and generalized anxiety. In 2010, it received approval for treating chronic musculoskeletal pain, including chronic low back pain.
How might an antidepressant work for chronic musculoskeletal pain? Duloxetine belongs to a class of antidepressant drugs known as serotonin-norepinephrine reuptake inhibitors (SNRIs). SNRIs enhance levels of two neurotransmitters in the brain, serotonin and norepinephrine. The overall effect, researchers believe, is to reduce pain signals throughout the central nervous system.
One pain condition frequently studied to determine how well duloxetine works is chronic low back pain, defined as lasting longer than three months. The condition is extremely common, estimated to affect about eight in 10 adults at some point in their lives. It’s a major cause of disability, and in severe cases, spinal steroid injections or even back surgery may be indicated. Today, with opioids for chronic pain strongly discouraged, patients hold out hopes for effective treatments that do not involve surgery and are not addictive. So duloxetine represents a possible alternative.
Results from a number of randomized placebo-controlled trials involving the use of duloxetine for low back pain conclude with recommendations that range from enthusiastic to only mildly positive, to be viewed with caution. A review of five studies, published in Cureus in 2021, affirmed that duloxetine was safe and effective and should be considered a “first-line option.” A more negative evaluation arose from a 2021 analysis in BMJ of 33 studies investigating the use of antidepressants for chronic low back pain. The effects of SNRIs were found to be “small and not clinically important for back pain,” but, as an accompanying editorial stated, “Some individuals…may gain a personal benefit.”
Most recently, a meta-analysis published in May by the Cochrane Collaboration concluded that of 25 different antidepressants reviewed, “the only antidepressant we are certain about for the treatment of chronic pain is duloxetine. Duloxetine was moderately efficacious across all outcomes at standard dose.” The authors also said, however, that “there is no ‘one size fits all’ with both antidepressants and pain. Adopting a person-centred approach is critical.”
Most people can take duloxetine without serious or persistent side effects, which may include constipation, dizziness, and drowsiness. Serious adverse effects are rare, but the drug does carry a “black box” warning that notes the risk of suicidal thinking in children and young adults. Chronic liver disease is a contraindication for duloxetine, and people who have or develop any indication of liver dysfunction (such as jaundice), or who drink substantial amounts of alcohol, also should not take the drug.
Like other types of antidepressants and all SNRIs, stopping duloxetine can provoke symptoms of withdrawal in some people. The symptoms—such as nausea, irritability, and dizziness—are typically of mild to moderate intensity and, like most withdrawal syndromes, they tend to resolve over time. Some people have no difficulty at all in stopping the drug. Still, it’s generally advised, when time comes to stop, to slowly discontinue duloxetine, reducing the dosage over the course of perhaps two to four weeks.
BOTTOM LINE: Whether you should try duloxetine for chronic musculoskeletal pain is a decision to make in consultation with your doctor. Your choice will depend on such factors as the type and severity of your pain, other drugs you may be taking, and the potential for adverse effects.
