Opioid induced hyperalgesia is real. What happens is that as soon as you start taking an opioid, the opioid and its metabolites promote the development of long-term increased pain sensitivity and negative mood. Right after the opioid medication is taken, the Mu opioid receptor effects predominate, when it wears off the the underlying neuroexcitatory and neuroinflammatory baseline changes are unmasked and patients experience worsening chronic pain and negative mood. Overtime, patients will seek higher and higher doses to overcome this rising baseline state of pain, thereby worsening the underlying hyperalgesic state.
When a chronic opioid patient arrives in distress. To effectively treat the pain, more opioids is not the answer. Instead, an opioid sparring, approach using antihyperalgesic medications is preferred.