Accidental Methadone Ingestion in an Infant

INTRODUCTION: We discuss accidental methadone intoxication in an 11-month-old female infant, review the literature, and stress the potential for child abuse among methadone-maintained caregivers. CASE: An 11-month-old female infant presented with lethargy. Vital signs were normal, and pupils were constricted. Sepsis workup revealed no evidence of bacterial infection. High venous pCO2 suggested respiratory acidosis. Urine toxicology revealed high concentrations of methadone and its metabolites, and the diagnosis of methadone intoxication was confirmed when 0.1 mg/kg intravenous naloxone normalized the child's behavior. Social service agency inquiries found that the child's grandfather had been prescribed methadone for acquired morphine addiction. He carried 5-mg methadone tablets in his pocket and had recently babysat the infant. The patient was subsequently discharged home with pediatric and community services follow-up. DISCUSSION: Methadone intoxication should be considered in children presenting with lethargy, miosis, and respiratory depression. Seventy-two percent of reported methadone poisoning patients are symptomatic, and unintentional poisoning is a real danger to children because small amounts can be fatal. There are also several case reports where the cause of intoxication was homicide by the parents. Initial management consists of establishing an airway, and naloxone may be indicated, before urine toxicology results are obtained, to help establish the diagnosis. However, if 2 doses do not reverse the child's symptoms, the diagnosis should be questioned. When repeated bolus doses of naloxone are indicated, a continuous infusion may be preferable.