Rapid Buprenorphine Initiations for Cardiac Emergencies in Patients on High-dose Methadone: A Case Report

Methadone remains the most utilized medication for opioid use disorder (MOUD) with significant mortality reduction. Methadone carries a black box warning for the prolongation of the corrected QT interval (QTc), which can be fatal. Buprenorphine is another mortality-reducing MOUD that does not carry this same risk and should be considered as an alternative in patients for whom methadone reinitiation is not feasible. However, given that buprenorphine is a high-affinity partial mu opioid receptor agonist, transition from methadone to buprenorphine can lead to precipitated withdrawal. Currently, there is no consensus on the preferred method for urgent transition from high-dose methadone to buprenorphine.

We highlight 2 patients with opioid use disorder (OUD) on high-dose methadone who required immediate cessation with rapid transition to buprenorphine due to life-threatening arrhythmias. One patient experienced precipitated withdrawal despite a short-acting full agonist opioid bridge, but was eventually stabilized with higher doses of buprenorphine. The other patient did not experience precipitated withdrawal during transition and did not require short-acting full agonist opioids.

Life-threatening arrhythmias are a rare but serious complication of methadone. If QTc prolongation limits the ability to reach a therapeutic methadone dose during reinitiation, transitioning to buprenorphine should be considered. Given the emergent nature of the transition in these cases, cross-titration with buprenorphine can be helpful. However, patient response remains variable and precipitated withdrawal can occur. Therefore, a thorough discussion with patients regarding risks and benefits, as well as an action plan for precipitated withdrawal, is necessary before initiation.