Unusual opioid withdrawal syndrome. A case-report

In a patient with advanced cancer, neurosurgery relieved severe pain that had been uncontrolled by very high doses of opioids. On reduction of opioid dosage he had visual and auditory hallucinations and showed deterioration of consciousness progressing to coma. Naloxone worsened his mental state whereas morphine restored it to normal. This syndrome may be related to opioid withdrawal at receptors other than the mu receptors that have been linked to analgesia and drug abuse.