Antidepressants show potential for postoperative pain

Dr. Ian Gilron, a professor and director of clinical pain research in the Department of Anesthesiology, and his team of seven researchers reviewed 15 trials to determine whether the use of antidepressants for pain relief post-surgery would work more effectively than painkillers such as opioids, local anesthetics, or acetaminophen.

Clinical trials are often used to answer questions about the efficacy of the off-label uses of drugs. In the case of antidepressants, their effects on postsurgical pain continue to be an area of research interest.

"For the past 50 years, it's been observed that antidepressants for other chronic pain conditions relieve pain independently of their effect on depression," says Dr. Gilron, who also works as an attending anesthesiologist at Kingston General Hospital (KGH). "Even with the best available medicines, there are still many people who experience postoperative pain. Reviewing the use of antidepressants to manage this pain was definitely an opportunity to be seized."

Pain around a surgical site can interfere with normal activities like walking; it can also prolong recovery from surgery.

After searching through three databases of trials, first author of the paper and fifth year anesthesiology resident Karen Wong sifted through 1,350 records from three different research databases to select the 15 trials for detailed review.

Trials were selected for review based on a patient's pain at rest and with movement, adverse effects of antidepressants, and other outcomes of using antidepressants for postsurgical pain.

Just over half of the trials examined showed a reduction in pain after use of antidepressants.

"These results are more than a coincidence," says Dr. Gilron. "We can conclude from this research review that, while it's premature to formally recommend these drugs be prescribed for pain, more definitive studies on these medications are necessary."

The research review, "Antidepressant drugs for prevention of acute and chronic postsurgical pain: early evidence and recommended future directions," took three years to complete and has been published in the September 2014 edition of Anesthesiology.