PHILADELPHIA — Michael Charles Meeney turned 26 in jail on March 2, a week after his arrest for misdemeanor heroin possession. But his entire life may as well boil down to an inglorious 30 seconds of tightly edited video, played on local news channels, that shows him nearly dying.

On Feb. 18 a closed-circuit surveillance camera captured him shooting heroin, then falling out of his seat on a crowded city bus in Philly suburb, Upper Darby. The video cuts to a police officer hovering over the unconscious man and applying a dose of the powerful overdose antidote naloxone.

Naloxone (sold under the brand name Narcan) has been the subject of increasing media attention since the Food and Drug Administration approved a nasal spray version of the drug in last November to reverse the effects of opioid overdose, namely severe respiratory depression that can be fatal if left untreated. Narcan works by reversing those symptoms. A number of police departments now outfit their officers with it, and changes to state laws have made the drug legal for sale over the counter in some pharmacies. In 2014, Pennsylvania passed a law that made naloxone available through a standing prescription to laypeople, including drug addicts themselves and their families.