# Development of an intranasal, long duration opioid antagonist to treat opioid overdose

> **NIH NIH U01** · OPIANT PHARMACEUTICALS, INC. · 2021 · $1,800,581

## Abstract

The diversion and misuse of prescription opioids, a resurgence in heroin use, and the emergence of 
illicit, high potency synthetic opioids such as fentanyl, has fueled what is now described as the 
‘opioid epidemic’. The most visible manifestation of the opioid epidemic is a dramatic increase in 
the number of overdose deaths, estimated at more than 33,000 in 2015, and the more than 1.25 
million hospital visits linked to opioid misuse. Heroin and synthetics like fentanyl, less 
expensive and often more accessible than prescription opioids, have now taken center stage as a 
serious public health concern. Naloxone is currently the only opioid antagonist available to treat 
opioid overdose. The approval of both an auto-injector (Evzio, 2014) and an intranasal spray 
(Narcan nasal spray, 2015) has enabled non-medically trained personnel (first responders, friends 
and family of overdose victims) to reliably administer naloxone in an emergency with no training. 
While effective in reversing opioid overdose, the half-life of naloxone is relatively short (t1/2 
~2h). This project describes the development and clinical evaluation of an intranasal formulation 
of nalmefene, a long acting opioid antagonist (t1/2 ~ 10.8 h). Nalmefene injection (Revex) was FDA 
approved to treat opioid overdose, but its marketing discontinued (2008) due to low sales. The 
objective of this project is to develop an intranasal formulation of nalmefene possessing the 
pharmacokinetic characteristics (Cmax, Tmax) of parenterally administered nalmefene.  A long acting 
opioid antagonist would be especially useful in rural areas, where access to emergency medical 
services may be delayed, and in situations where exposure to an unidentified opioid is either 
anticipated or suspected (for example, by law enforcement and customs officials).

## Key facts

- **NIH application ID:** 9901501
- **Project number:** 5U01DA046093-03
- **Recipient organization:** OPIANT PHARMACEUTICALS, INC.
- **Principal Investigator:** Roger Crystal
- **Activity code:** U01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $1,800,581
- **Award type:** 5
- **Project period:** 2018-05-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9901501

## Citation

> US National Institutes of Health, RePORTER application 9901501, Development of an intranasal, long duration opioid antagonist to treat opioid overdose (5U01DA046093-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9901501. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*