Methadone-Induced Hypoglycemia in a Hospitalized Patient

Methadone is used as an agent for chronic pain and management of opioid use disorder. While similar pharmacologically to other opioids, methadone does have unique characteristics, including long half-life, low cost, and high oral bioavailability. While advantageous in some ways, methadone is associated with unique adverse effects not seen with other opioids (ie, hypoglycemia). In this case, we describe a patient in his late-60s with opioid use disorder on chronic methadone who presents with symptoms of generalized weakness, fatigue, and decreased appetite for 2 days. The hospital course was complicated by hypoglycemia, without obvious cause other than methadone-induced hypoglycemia. The patient was managed with supportive care to maintain normoglycemia. He was continued on methadone and instructed to follow-up with his opioid treatment program to assess for dose de-escalation to minimize future hypoglycemia risk. While other case reports of methadone-induced hypoglycemia highlight the risk of this adverse effect, our case highlights the importance of assessing methadone as a cause of hypoglycemia and provides discussion around the legality of dose de-escalation at discharge from an acute care setting.