Senator Patrick Leahy (D-Vt.) and thirty of his colleagues sent a letter to Kaléo Pharmaceuticals Wednesday to question the company's price hike of its opioid-overdose-reversing device, Evzio.

As Ars has reported before, Evzio’s price rose dramatically over a short period of time—going from $690 in 2014 to $4,500 currently, according to the letter. Evzio is an easy-to-use auto-injector that delivers a dose of naloxone, a generic drug that blocks and reverses deadly opioid overdoses.

Amid the price increases, the country has been gripped by an epidemic of opioid addiction and overdoses. The CDC now estimates that 91 people die every day from an opioid overdose, and some hard-hit areas have even run out of morgue space.

Policymakers and health officials have been scrambling to get out ahead of the problem. Efforts include urging doctors to reduce opioid prescriptions, working on better addiction treatments and opioid alternatives, and arming everyone from first responders to grocery stores with naloxone. Amid those efforts, “this startling price hike is very concerning,” the senators wrote in their letter (PDF).

The company has argued that the high list price isn’t what most consumers will pay or even see. But the senators expressed worry for those who might fall through the cracks and also for state and local agencies that want to buy the devices in bulk.

The senators requested that the company answer three questions: what is the detailed price structure for Evzio, including production costs, and why has the price increased? How many devices has the company set aside for donation and how is it gauging whether first responders, states, and other public entities have adequate access? And what is the total amount of federal reimbursements Evzio received in the last 12 months? (Related to that question, they also ask: what's the percentage of customers who used federal funds to buy Evzio in that same period?)

Kaléo has not yet responded to Ars’ request for comment. In a statement e-mailed to The Consumerist, Kaléo CEO Spencer Williamson said:

“We received the letter from the Senators and are in communication with them to ensure all questions are addressed. Our first priority remains ensuring that patients can access EVZIO. In fact, with the launch of kaléo’s enhanced patient access program, more Americans are able to obtain this life-saving product for $0 out-of-pocket than any time in history. “Details of how we are ensuring the broadest access to EVZIO for patients and their loved ones through our patient access program include: For the more than 200 million Americans with commercial insurance and a prescription, they can get EVZIO for $0 out-of-pocket.

For patients who do not have government or commercial insurance, and have a household income of less than $100,000, they can also receive EVZIO for $0 out-of-pocket.

For those paying cash, the price is $360. … No naloxone product, branded or even generic, is less expensive for commercially insured patients, or patients without insurance and incomes below $100,000 a year, than EVZIO. “Since EVZIO was not designed for the bulk purchase market, which is comprised primarily of first responder agencies, health departments and harm reduction organizations, we developed the kaléo Cares Product Donation program to provide EVZIO free of charge and ensure communities in need can access our product. To date, we have donated nearly 200,000 doses of EVZIO and it has been reported to us that 2,800 lives have been saved through this program.

The other senators who signed the letter are: Sens. Al Franken (D-Minn.), Christopher Murphy (D-Conn.), Jack Reed (D-R.I.), Dick Durbin (D-Ill.), Sheldon Whitehouse (D-R.I.), Maria Cantwell (D-Wash.), Dianne Feinstein (D-Calif.), Tammy Baldwin (D-Wis.), Claire McCaskill (D-Mo.), Jeanne Shaheen (D-N.H.), Angus King (I-Maine), Richard Blumenthal (D-Conn.), Edward J. Markey (D-Mass.), Maggie Hassan (D-N.H.), Amy Klobuchar (D-Minn.), Heidi Heitkamp (D-N.D.), Elizabeth Warren (D-Mass.), Tammy Duckworth (D-Ill.), Kirsten Gillibrand (D-N.Y.), Joe Donnelly (D-Ind.), Jon Tester (D-Mont.), Bernie Sanders (I-Vt.), Sherrod Brown (D-Ohio), Debbie Stabenow (D-Mich.), Tom Udall (D-N.M.), Tim Kaine (D-Va), Mark Warner, (D-Va.), Gary Peters (D-Mich.), Jeff Merkley (D-Ore.), and Cory Booker (D-NJ).