Ketamine is a drug that doctors often use to help people sleep during surgeries or for short-term pain relief.
But in recent years, some doctors have started using it for something else: treating long-lasting (chronic) pain.
This is called “off-label” use, which means the drug is being used in a way that’s different from what it was officially approved for.
Some people with conditions like nerve pain, fibromyalgia, or complex regional pain syndrome have been given ketamine to help manage their pain. But a new review says we should be careful.
Researchers from UNSW Sydney, NeuRA, and Brunel University of London looked at 67 studies that involved more than 2,300 adults. They wanted to find out if ketamine or other similar drugs called NMDA receptor antagonists actually help with chronic pain.
These drugs are thought to block pain signals in the brain. The review included five of these drugs: ketamine, memantine, dextromethorphan, amantadine, and magnesium.
After going through all the studies, the researchers found that there is no strong evidence showing ketamine truly works for chronic pain. In fact, many of the studies had small sample sizes or other issues, so their results were not very reliable.
What was clear, however, is that ketamine often caused side effects. People reported feeling confused, paranoid, or seeing things that weren’t there. Other common problems included nausea and vomiting.
“We’re not saying ketamine doesn’t work, but the truth is, we don’t really know,” said Michael Ferraro, a researcher at UNSW and one of the main authors of the study. “Right now, the science is too uncertain.”
The team also looked at different doses and how ketamine was given, such as through an IV, but still found no clear benefits. In fact, the side effects were often worse when the drug was given through a vein.
Surprisingly, none of the studies looked at two important things: whether ketamine helped people feel less depressed or if it helped them stop using other pain drugs like opioids. This is important because ketamine is often suggested for people who have depression or who are trying to lower their use of opioids.
Neil O’Connell, a professor at Brunel University and co-author of the review, said, “Ketamine and similar drugs are being used for chronic pain around the world, but we don’t have good evidence that they’re really helping. That’s a big red flag.”
The researchers say their work should make doctors and patients think carefully before using ketamine for chronic pain. They are not against using it, but they believe we need better studies to know if it actually helps.
James McAuley, another co-author, said, “We’ve already seen problems with opioids being used for chronic pain. Now ketamine is being used in a similar way. We need to make sure we don’t repeat the same mistakes.”
In the end, the researchers call for better quality research. They hope future studies will give clearer answers about whether ketamine is truly helpful or not. Until then, doctors and patients should be cautious.
If you care about pain management, please read studies about Scientists find a new drug for chronic nerve pain and findings of Scientists find a new, less-invasive way to tackle knee pain.
For more about pain, please read studies about Scientists find a new way to manage knee pain and findings of Promising new drug offers hope for chronic nerve pain relief.
The study is published in Cochrane Database of Systematic Reviews.
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