Contributor: Donald Stader, MD Educational Pearls: Not uncommon for patients presenting after opiate overdose and narcan administration to be observed for 4-6 hours This has been based more on tradition than evidence Observation periods for overdose may vary based on the opiate(s) used Fentanyl and heroin have half lives of about 2 hours, while oxycodone and methadone have significantly longer half lives.  HOUR trial attempted to externally validate a scoring tool for stratification of low risk patients appropriate for discharge after 1 hour References Clemency BM, Eggleston W, Shaw EW, Cheung M, Pokoj NS, Manka MA, Giordano DJ, Serafin L, Yu H, Lindstrom HA, Hostler D. Hospital Observation Upon Reversal (HOUR) With Naloxone: A Prospective Clinical Prediction Rule Validation Study. Acad Emerg Med. 2019 Jan;26(1):7-15. doi: 10.1111/acem.13567. Epub 2018 Dec 28. PMID: 30592101. Summarized by Will Dewispelaere, MD | Edited by Erik Verzemnieks, MD