Intranasal overdose reversal formulations: a rapid review of available agents

The opioid epidemic continues to pose a significant threat to public health. Naloxone, a potent opioid antagonist, has proven to be a crucial tool in reversing opioid overdoses. Efforts to increase access to overdose reversal agents, initially given by injection in hospitals and emergency environments, resulted in the development of intranasal (IN) forms of naloxone, and more recently, nalmefene. This rapid review examines the currently available IN overdose reversal agents in the United States, focusing on their dosing, efficacy, and prescription status. We conducted a comprehensive search of the FDA Electronic Drug and Listing System (eDRLS) to identify all approved naloxone and nalmefene formulations in 2024. The search yielded nine available overdose reversal agents, including generic formulations of naloxone available over the counter and accessible to the public. Additionally, newer agents, such as nalmefene, offer longer-acting effects and may provide additional benefits in certain overdose scenarios. As the opioid crisis evolves, it is essential to stay informed about the latest advancements in formulations of reversal agents. By understanding the characteristics and availability status of available agents, health care providers, public health officials, and individuals can make informed decisions about the most appropriate overdose treatment strategies.