Delayed hypoxic encephalopathy: a rare complication of methadone poisoning in two cases

Methadone is a kind of opioid that is used to reduce the pain of addicts who decide to withdraw drugs. Sometimes due to a lack of appropriate cautions, this drug will be accessible to children, and poisoning might occur. Methadone poisoning usually presents with the loss of consciousness and pinpoint pupils. Herein, we present two cases of delayed hypoxic encephalopathy that had been poisoned by methadone. CASE PRESENTATION: The first case was a 4-year-old female patient who firstly presented with nausea and vomiting; then, the case was discharged; however, 1 week later, the case was returned with the loss of consciousness and poisoning by methadone confirmed in her urine. Again 2 weeks later, the case returned to the hospital, developing weakness of limbs, slurred speech, and abnormal movement of her limbs. The second case was an 11-year-old female patient who was admitted to an intensive care unit due to the loss of consciousness and methadone poisoning. After providing supporting care, she was discharged but returned to the hospital 5 days later. She developed weakness of limbs, abnormal movement of tongue and extremities, and slurred speech. In their last admission, the magnetic resonance imaging of the patients revealed hypoxic damage in the basal ganglia; therefore, delayed hypoxic encephalopathy was confirmed. CONCLUSION: Patients with methadone poisoning should be observed for at least 1 and a half months after poisoning. Moreover, parents should notice that in the case of observing abnormal neurologic manifestations bring their child as soon as possible to a hospital to prevent irreversible damage to the brain.