Opioid-induced hyperalgesia (OIH) is a condition where the same medication that is prescribed to alleviate your pain causes more pain. After being on opioid therapy, people with OIH notice that pain sensitivity around their original ailment worsens and pain tolerance may be low in general. For example, say you’re a chronic pain patient taking opioids for back pain. If you develop OIH, you may feel like the medication isn’t alleviating your back pain anymore. You may also experience abnormal pain sensitivity to something as innocuous as a light touch.
Opioid-induced hyperalgesia involves complex changes in human molecular mechanisms. Opioids like oxycodone, morphine, and hydrocodone affect pain perception by working on brain receptors that receive pain signals. So, if you’re having back pain or other discomfort, these drugs block or decrease pain signals from reaching your brain. This process is what provides you relief from discomfort.
Development of OIH occurs because of your body’s defense system. After chronic opioid use, the body tries to correct the discrepancy in pain receptors and the CNS signaling system by switching on other neural pathways and pain signals and making new connections. This can sometimes cause hyperactivation of nerve cells and pain receptors. When this happens, you no longer get relief from painkillers, and you feel over sensitive to pain in other parts of your body.
Scientists are still trying to determine why some people are more likely to develop OIH as well as why some people experience it more quickly. Most cases of opioid-induced hyperalgesia result from chronic pain medicine use, however some people may develop OIH after short stints on painkillers or after acute opioid therapy. Research suggests OIH may have a genetic component, which could help explain why some develop it more quickly. In general, studies show that high doses of opioids over long periods of time often results in some increased pain sensitivity.
Opioid-induced hyperalgesia presents differently. Some people may feel intense pain, while others have milder pain symptoms. The opioid dose and time it takes to develop OIH also varies.
Symptoms of opioid-induced hyperalgesia may include the following:
- Your painkiller may seem like it’s not working as well.
- Your original pain may feel worse or like it covers more area than initially.
- You start feeling unexplained pain in other parts of the body.
- Pain from the original diagnosis is worse even though your condition hasn’t worsened.
- Pain from regular stimuli is much worse and longer than it should be (ex. a needle prick).
- Even gentle or benign skin touches feel painful.
Opioid-Induced Hyperalgesia Vs. Opioid Tolerance
The symptoms of opioid-induced hyperalgesia and opioid tolerance have some similarities, but the conditions are different. When you develop a tolerance to opioids, your body needs more of the drugs to get the desired effect. When your physician increases your pain meds, you typically feel some relief again. In cases of opioid-induced hyperalgesia, increasing opioid doses does not provide relief, and can make pain worse.
As far as opioid tolerance, it’s a slippery slope between it and opioid addiction. The risk of opioid addiction increases if you have co-occurring mental health disorders or other underlying challenges. You may find that beyond physical relief, the effects of opioids also help numb emotional pain. Opioid use can escalate quickly, becoming a way to self-medicate. Because of their highly addictive nature, many physicians are moving away from using opioids for pain management except in cases of surgery and palliative care.
There are a few approaches to treating OIH. Depending on how long you’ve been taking opioids, quitting cold turkey can bring on painful and dangerous withdrawal symptoms. Some physicians will taper your doses over a determined period of time. Another approach is switching to smaller doses of another opioid or a partial opioid agonist like buprenorphine. These treatments can sometimes minimize the pain that accompanies OIH during the transition to other pain management approaches.
There’s some evidence that ketamine, an NMDA receptor antagonist, can be an effective OIH treatment. It can block the pain receptors that have become hypersensitive. Some physicians or treatment programs may use this. Other OIH treatments may include acetaminophen, antidepressants, gabapentin, and anti-inflammatory drugs.
If you’re using opioids for the wrong reasons, reach out for help. Around 21 to 29% of chronic pain patients misuse their prescription opioids according to The National Institute of Drug Abuse. Opioid abuse can cause long-term damage to your physical and mental health and have deadly consequences. In 2020, 69,710 people died from opioid overdoses. Don’t become a statistic. We can help. Get a free, confidential consultation: 844.952.2517