WASHINGTON — The U.S. is in the midst of a massive opioid epidemic, with tens of thousands of overdose deaths per year, and millions more addicted to illicit drugs.

The New York Times reports that on Thursday, U.S. Surgeon General Jerome Adams issued a rare advisory urging more people to carry the overdose-reversing drug Naloxone. The last advisory had been sent out 13 years ago, when women were told not to consume alcohol while pregnant.

During an overdose, synthetic drugs like heroin or fentanyl flood the brain and lock onto the opiate receptors, causing breathing to become dangerously slow.

According to the advisory from the Surgeon General's Office, Naloxone can reverse the effects of an overdose and comes in two forms — a nasal spray, and a syringe that should be injected into the muscles of the thigh, buttocks or arms.

The emergency medication works by knocking the opioids out of the receptors in the brain — blocking and temporarily reversing their effects for 30 to 90 minutes.

Police officers and medical responders are among those who have been using Naloxone to counter overdose deaths.

The life-saving drug is also available at local pharmacies and local health departments.