High-Dose Naloxone Nasal Spray Rezenopy Gets FDA Approval

The Food and Drug Administration (FDA) has approved Rezenopy (naloxone hydrochloride) nasal spray for the emergency treatment of known or suspected opioid overdose, as manifested by respiratory and/or central nervous system depression in adult and pediatric patients.

Rezenopy is an opioid antagonist that reverses the effects of opioids, including respiratory depression, sedation, and hypotension. The nasal spray product delivers 10mg of naloxone hydrochloride in a single dose. Rezenopy is intended for immediate administration as emergency therapy in settings where opioids may be present.

The approval was supported by pharmacokinetic data, which established the safety and efficacy of the product. The most common adverse reactions reported with Rezenopy were upper abdominal pain, nasopharyngitis and dysgeusia. 

Naloxone HCl is currently available in a nasal spray formulation in 3mg (Rivive), 4mg (Narcan Nasal Spray), and 8mg (Kloxxado) dosage strengths. A recent study comparing a higher dose naloxone nasal spray (8mg) to a lower dose one (4mg) showed no significant difference in survival or in the number of doses administered to recipients. Stronger opioid antagonists were found to be associated with a higher prevalence of opioid withdrawal signs and symptoms.