The price of a life-saving overdose treatment has increased 680% in the last 3 years

An emergency medication often referred to as an "antidote" for opioid overdoses has been skyrocketing in price over the last few years.

The device, the only auto-injector version of naloxone, is called Evzio, and it's made by Kaleo.

Naloxone instantly reverses opioid overdoses by blocking the drug from interacting with the brain's receptors. It has been on the market since 1971.

In 2014, when Evzio was approved in the US, the list price was $575 for a two-pack. Now, it has a list price of $4,500 - an increase of 680%.

Kaleo, a private company based in Richmond, Virginia, also owns Auvi-Q, the emergency epinephrine device that made headlines in October 2016 when the company announced it would come back to the US as competition to the EpiPen after getting recalled a year earlier. The Auvi-Q and Evzio use the same auto-injector technology to deliver their respective emergency medications.

The list price for a two-pack of the Auvi-Q comes in at $4,500 as well, though the company maintains that the cash price for people without insurance is $360 and that more than 200 million people will be able to get the device with a $0 copay. That list price is roughly 640% higher than the list price of the EpiPen, which was singled out in August 2016 for increasing the price of a two-pack by 500% over the course of seven years.

Now, the list prices of the two drugs is catching the eye of Democratic Senator Amy Klobuchar of Minnesota, who sent a letter Friday to Kaleo asking for more information about the company's pricing strategy.

List prices don't often tell the whole story when it comes to a drug's price. There are other players in the system that each take a piece, which means that what a drugmaker actually receives could be lower even as the list price rises. Kaleo declined to comment on its average net price for Evzio.

"When setting the 'list' price for products, kaléo always starts with the needs of the patient first and then engages with multiple stakeholders in the healthcare system," Kaleo's vice president of corporate affairs Mark Herzog said in a statement emailed to Business Insider. "Following these discussions, in order to help ensure our product is available as an option to most patients for $0 out-of-pocket, we set the list price at $4500."

The rationale of the company's pricing strategy didn't seem to satisfy Klobuchar.

"I understand that Kaleo is trying to mitigate the impact on consumers by providing Evzio for free to cities, first responders, and drug treatment programs, and offering various programs to help ensure that no consumer pays the $4,500 price for Auvi-Q," Klobuchar wrote. "While these subsidies and programs are noteworthy, I am concerned that they do not address the underlying problem of rising prescription drug costs."

This isn't the first time rising naloxone prices have been called out. Until recently, Evzio's price had been $3,750 per two-pack. And across the board, naloxone prices have been skyrocketing, as Business Insider's Harrison Jacobs has reported.

However, most other naloxone options - syringes, and a nasal spray - have list prices in the hundreds for sets of 10 vials or two nose sprays. As a proportion of total naloxone market, Evzio made up roughly a third of prescriptions in 2016, according to data from IMS Health.

It remains to be seen how many prescriptions transfer from the EpiPen to the Auvi-Q. Before it was recalled, Auvi-Q only had a small share of the market at a list price of around $500.

But its high list price is already turning off health insurers and pharmacy benefits managers. FiercePharma reports that Cigna, Humana, and the pharmacy benefits manager Express Scripts have come out against the pricing strategy for Auvi-Q, while Aetna is putting it on restricted coverage. The device officially launches in the US on February 14.

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