What is Narcan, the drug found in Hayden Panettiere's apartment after her death?

Actress Hayden Panettiere passed away on Sunday, August 16, at the age of 36 in her apartment located in Greenville, South Carolina. First responders arrived at the scene following an emergency call placed by a friend of the actress.

At the apartment, emergency teams discovered evidence pointing to a potential opioid overdose. Authorities also recovered Narcan, a medication commonly used to reverse the effects of opioid overdoses, during their investigation into the incident.