Epidural analgesia for acute ischemic pain after intra-arterial zolpidem injection in opioid-addicted patient-A case report.

A patient taking opioid maintenance therapy unintentionally injected dissolved zolpidem pills into the femoral artery and suffered acute limb ischemia. High amounts of opioids with supplemental therapies were inefficient for intractable ischemic pain, suggesting the presence of opioid-induced hyperalgesia (OIH). Epidural analgesia efficiently relieved pain and symptoms of OIH.