New FDA Approval Marks a First in the Fight Against Opioid Overdose

This week, the US Food and Drug Administration (FDA) approved Zurnai, the first nalmefene hydrochloride auto-injector for the emergency treatment of known or suspected opioid overdose in adults and pediatric patients 12 years of age and older.

Drug overdoses continue to represent a major public health crisis in the United States. As noted by the FDA, more than 107,000 reported fatal overdoses occurred in 2023, primarily driven by synthetic opioids like fentanyl. Nalmefene and naloxone are two available options used for the reversal of opioid overdose. Specifically, nalmefene is an opioid receptor antagonist that, if administered quickly, can reverse the effects of opioid overdose, including respiratory depression, sedation, and hypotension.

Zurnai, a single-dose, prefilled auto-injector available only by prescription, delivers nalmefene 1.5 mg either subcutaneously or intramuscularly.

The approval of Zurnai is supported by safety and pharmacokinetic studies, as well as a study in healthy individuals who use opioids recreationally. The most common side effects of Zurnai are feeling hot, dizziness, nausea, headache, chills, vomiting, feeling pain from actions that aren’t typically painful, palpitations, ringing or buzzing in the ear, ear discomfort, feeling abnormal, a burning sensation, hot flush, and irritability.

The FDA noted that the use of nalmefene hydrochloride in patients who are opioid dependent may result in opioid withdrawal characterized by the following signs and symptoms: body aches, diarrhea, tachycardia, fever, runny nose, sneezing, goosebumps, sweating, yawning, nausea or vomiting, nervousness, restlessness or irritability, shivering or trembling, abdominal cramps, weakness, and increased blood pressure.

“The FDA remains focused on broadening access to opioid overdose reversal agents, including naloxone and nalmefene. Today’s approval adds a new nalmefene product and route of administration to support greater options for opioid overdose reversal,” said FDA Commissioner Robert M. Califf, MD, via a press release. “Since launching the FDA Overdose Prevention Framework in 2022, the agency continues to build upon efforts that address the overdose crisis currently impacting the nation.”