Introduction

Sublingual Naloxone combined with Buprenorphine in various formulations has been approved for treatment of opioid use disorder. Despite its low bioavailability, Naloxone can reach systemic circulation and cause adverse effects. Peripheral edema has been reported as a side effect of Buprenorphine/Naloxone but not as a side effect of Naloxone in post-marketing data as well as other reports elsewhere.

Case description

A case report is presented which includes a patient that experienced bilateral peripheral edema related to Buprenorphine/Naloxone combination. After the patient was switched to monotherapy with Buprenorphine by itself, the side effects resolved.

Commentary

Naloxone given in sublingual formulation may have oral bioavailability despite previous reports. After reaching systemic circulation, Naloxone has potential for causing side effects. Peripheral edema may be caused by Naloxone’s role in antagonising the endogenous opioid system resulting in capillary permeability.