TIRR Memorial Hermann Researchers Assess the Impact of Opioid Exposure on Patients with SCI

Pain due to spinal cord injury (SCI) reduces patient quality of life and can be difficult to treat. Opioids are an effective tool for managing neuropathic pain, but research in animal models suggests that opioids may do more harm than good in patients with SCI. An ongoing research project at TIRR Memorial Hermann is exploring the impact of opioid exposure on patients recovering from the condition.

“The hypothesis came from animal research,” explains Argyrios Stampas, MD, MS, the director of spinal cord injury medicine research at TIRR Memorial Hermann. “When rats are administered morphine, their spinal cord injuries are bigger than those that aren’t administered morphine. There are receptors for opioids that increase the inflammatory response around the injury and cause further damage in the early period of spinal cord injury.”

In addition to larger spinal cord lesions, animals exposed to opioids also had trouble walking, had more pain and were more likely to experience depression. Dr. Stampas uses these animal data to help patients decrease their opioid exposure during recovery from SCI.

“Because of the opioid epidemic, part of my role when I was admitting patients with spinal cord injury was to help them come off of opiates because many patients would come from the acute care hospital to rehabilitation on opioids,” Dr. Stampas says. “It was very difficult because they do have pain. I would tell patients what we’ve seen in animals and that it's very likely to be happening in humans to some extent. If you really want to optimize your chances of recovery, one of the first things I would stop would be opioids if possible, or at least reduce or limit them. I found that to be the most successful argument, but I didn’t have that human data.”

At TIRR Memorial Hermann, Dr. Stampas performed a retrospective study to evaluate how medication administered at the scene of an accident or within 24 hours of an injury affected outcomes. In this study, Dr. Stampas saw effects like those reported in animals, but more data are needed.

“We found that the people who are given the highest dose of opioids within 24 hours of injury had worse pain scores at one year and they are at higher risk for depression at one year,” Dr. Stampas notes. “We did not find the change in motor recovery, but I think that’s a limitation to the small number of people in our initial study.”

Now, through the Texas SCI Model System program, funded by the National Institute on Disability, Independent Living and Rehabilitation Research (NIDILRR), TIRR Memorial Hermann is leading a research program that will expand its access to patient data and bring in other study sites for researchers to examine whether opioids given at the scene of an accident affect outcomes of spinal cord injury in humans.

As part of NIDILRR’s Model Systems program, participating centers must conduct one study on their own and also collaborate on Module projects with others in the program. TIRR Memorial Hermann’s Module project on opioids has been selected as primary among the four presented for the next funding cycle.

Data collected from hospitals in Boston, Cleveland, Dallas and Washington, D.C. will include the medications administered within 24 hours of the injury, as well as those given at the hospital and at admission and discharge from rehabilitation.

“There are tremendous implications for this study,” Dr. Stampas says. “From what I can tell, these opioids are being administered in a way that I can’t see a pattern. People receiving the highest doses of medication don’t necessarily have the highest pain scores. If the opioid administration is based on the discretion of the administrators of these medications, then it is very likely that we can make a big difference if this knowledge holds up to be true. People could consider fewer doses or less-strong medications.”

Dr. Stampas is looking forward to the information that will be gained from this study and anticipates that it will have a positive impact on patient care.

“It’s an important time during which we can make an impact,” Dr. Stampas notes. “Managing traumatic events like spinal cord injury, similar to stroke, requires doing something quickly. It’s important to look at the things that we may take for granted—the usual care practices that could be causing harm. I think it’s worthwhile to look at simple clinical trials that could help us answer these types of questions.”