Opioid-induced Hyperalgesia complicates treatment of pain: concept, diagnosis and treatment

Opioid induced hyperlagesia (OIH) is caused by excitation of the neurons and microglia in the spinal cord after exposure to opioids. All opioids are able to produce OIH, but some of them do it stronger than others. In this article the concept of OIH as well as the diagnosis and treatment strategies will be discussed. The most successful strategy is the dose reduction and modification of NMDA receptor activity in the spinal cord. This can be secured by the use of ketamine, gabapentinoids, propofol, magnesium salts, paracetamol and experimentally, ultra-low doses of opioid antagonists.