Summary: A new study by University of Sydney researchers found that there is little evidence that antidepressants are of much use in chronic pain in older adults, except for a few conditions. They found that most guidelines are based on a small number of clinical studies done in relatively young adults.
One of the new studies by the University of Sydney shows that despite the widespread use of antidepressants for managing chronic pain in older adults, evidence is limited in favor of their use.
Managing chronic pain is quite challenging, more so in older adults. Moreover, the prevalence of chronic pain significantly increases with advancing age. This is because most older adults, especially those older than 65, live with one or another health condition. Chronic pain specialists have often pointed out that older adults require tailored approaches to pain management.
Even many clinical guidelines recommend using antidepressants for managing chronic pain, and this is despite the fact that there is limited evidence. There are very few high-quality studies that support their use.
So, this new study found that in the last 40 years, despite the rising use of antidepressants for managing pain, just about 15 clinical studies focused on the role of antidepressants in managing pain in older adults. So, this new study fills the long-existing gap since it looks into the quality of existing evidence. This study particularly analyzed the benefits of commonly prescribed antidepressants for chronic pain, like amitriptyline and duloxetine.
One of the lead investigators from the University, Dr. Sujita Narayan, says that most of the international guidelines for managing chronic pain by using antidepressants are based on studies that did not include older adults or were in small numbers. However, health professionals, including those in interventional pain management in St. Louis, often use these treatment guidelines to manage common painful conditions in older adults, like knee osteoarthritis.
Most busy professionals lack time to go deep into the evidence quality, and thus, they are more likely to use or consult various clinical guidelines.
Further, older adults have some specific issues, and they are more likely to experience certain side effects like feeling dizzy, falling, getting injured, or having impaired judgment after taking such drugs for their chronic pain. Therefore, it is no surprise that many older adults even stop taking these drugs.
Additionally, what treatment guidelines have omitted is the issue of withdrawal after prolonged use of antidepressants. Discontinuing antidepressant use can be quite challenging, and this may cause withdrawal symptoms similar to opioids. It means that antidepressants must be withdrawn from any treatment plan gradually by slowly tapering the dosage.
Researchers say that they did find some evidence that antidepressants may work in some instances. Thus, for example, they found that duloxetine may help older adults living with osteoarthritis knee pain.
However, researchers noted that most evidence comes from short-term studies that have used duloxetine for about two to four months. It isn’t clear if the benefit of using antidepressants persists in the long run, as there are no studies that continued for 12 months or more. So, patients and doctors, including chronic pain specialists, need to know this when considering duloxetine for knee osteoarthritis. They need to understand that its benefits might be limited and not persistent, and long-term risks might be greater.
Further, most of the evidence favoring their use comes from small clinical studies with fewer than 100 participants. Not only that but most of those studies that demonstrated the benefits of antidepressants were funded by the industry.
Hence, researchers say that there is a need to update specific guidelines. Further, they recommend using a multi-dimensional approach to managing chronic pain that may include various non-pharmacological approaches like physical exercise and cognitive behavior therapy.
Investigators of the current study concluded that it is unwise to base clinical recommendations on small clinical trials done in younger adults. Older adults are different, and they respond to various medications differently.
Source:
Narayan, S. W., Naganathan, V., Vizza, L., Underwood, M., Ivers, R., McLachlan, A. J., Zhou, L., Singh, R., Tao, S., Xi, X., & Abdel Shaheed, C. (n.d.). Efficacy and safety of antidepressants for pain in older adults: A systematic review and meta-analysis. British Journal of Clinical Pharmacology, n/a(n/a). https://doi.org/10.1111/bcp.16234