Just a few years ago, naloxone was a relatively obscure drug that few people outside of the medical community knew about. Fast forward to today, and most Americans have heard of it -- even if they can't recall its name.

Virginia Gov. Terry McAuliffe says he always carries it on him. New Mexico Gov. Susana Martinez signed a law this year that requires all fire and police departments to keep it in stock. A few cities now let people buy it at the pharmacy without a prescription.

Naloxone is the life-saving antidote to an opioid overdose, reversing symptoms like respiratory failure and unconsciousness. In July 2016, the North Carolina Harm Reduction Coalition estimated that 38 states have at least one police department requiring officers to carry it. But with no end to the opioid epidemic in sight and the price of naloxone on the rise, public officials are starting to worry that they won’t be able to afford it much longer.

Kaleo Pharma, for example, has raised the price of a twin pack of injectable naloxone from $690 in 2014 to $4,500. Even the price of generic injectables has doubled in the last few years, with one now costing $150 and another $40. In the meantime, many places have switched to using the nasal injection form of naloxone. The price for that has stayed steady, $75 for two doses.

Still, with an average of 91 opioid overdose deaths a day in the U.S., the bill can quickly add up.

Baltimore has already started rationing the drug. Dr. Leana Wen, the city's health commissioner, calls it a “heartbreaking decision.” They’ve allocated it for clients in their needle exchange program and people working in areas with high rates of opioid abuse -- but they're no longer giving it to all police officers, who are often the first to respond to overdoses. 

Maryland Gov. Larry Hogan declared the opioid epidemic a public health emergency in March, and the state was awarded a $20 million grant over two years from the federal 21st Century Cures Act to battle it. But Wen says there's no timetable for when they’ll get that money. 

A Kaleo Pharma spokesperson told Kaiser Health News that the more-than-600-percent price hike was necessary “to subsidize programs that do not offer co-payments.”

Medical experts find that reasoning a bit flimsy.

“It’s not a complicated molecule to synthesize. It’s not a drug where you need a special type of yeast or grow a special kind of bacteria. We were able to make it so cheaply for so long,” says Eric Ketcham, medical director of the emergency department at San Juan Medical Center in Farmington, N.M.

When New Mexico's governor signed legislation to require all law enforcement agencies to keep naloxone in stock, it didn't include any funding. Ketcham says that's going to hinder their ability to adhere to the law.

“These rural fire departments just don’t have it in their budget," he says. "In Santa Fe, a do-gooder nonprofit is helping to distribute it. I don’t have that in Farmington."

Medicaid, the federal-state health-care program, covers the price of naloxone, but fire and police departments can't bill Medicaid. In response, some agencies throughout the country have partnered with local pharmacies who will bill Medicaid on their behalf.

Of course, all these questions around availability of naloxone would be exacerbated if the U.S. Senate's health bill becomes law. That legislation, in its most recent form, would end Medicaid expansion by 2020 and cut federal Medicaid spending by 26 percent, or $772 billion, over the next decade. The nonpartisan Congressional Budget Office estimates that it would leave 22 million more people uninsured by 2026.

The bill has been tabled for the foreseeable future while GOP Majority Leader Mitch McConnell rewrites it to, among other things, "provide tens of billions of dollars more for opioid treatment," reports The Washington Post.

If Medicaid does stop being able to cover naloxone and the price continues to increase, health officials worry what will happen to the epidemic at large.

“For many of my patients," says Ketcham, "that experience of being rescued was a defining moment for them that they need to get help."