The EpiPen is an auto-injection device sold by the drug company Mylan that delivers a pre-measured dose of the drug epinephrine to a person who is suffering a life-threatening allergic reaction caused by anything from a peanut allergy to bee stings.

While the drug has become the go-to device for quick response in an emergency situation, used by both emergency medical professionals and the public, the wholesale price of EpiPens hit an all-time high in August 2016. The pens are used to help patients suffering from symptoms of anaphylaxis, a severe form of shock caused by an allergic response. One of the most dangerous symptoms is that it can quickly cause swelling in the throat that blocks the airway.

According to the prescription drug price comparison tool, GoodRX, the out-of-pocket cash price for the drug is currently anywhere from $728 to $840, depending on the pharmacy. Current media reports suggest the price increase has created something of a crisis, particularly as children with allergies begin preparing to return to school for the Fall 2016 session.

It’s also causing many to question why the drug’s pricing has surged so high. A 1 mL vial of epinephrine, the same drug in the EpiPens, is sold for $4.49 by medical supplier Ace Surgical Supply. Meanwhile an adult dose EpiPen contains less: only 0.3 mL.

A September 2015 report by Bloomberg on the drug’s rapid price boost describes how Mylan purchased the EpiPen from Merck in 2007 and through a steady juggernaut of marketing and lobbying made it as synonymous with epinephrine auto-injectors as Kleenex has become facial tissue. Bloomberg notes each pen, which are sold in packs of two, contains about $1 worth of medicine. In the same year, Bloomberg reported the cost of the drug surged 32%:

In 2007, a two-pack of the epinephrine-filled devices went for $56.64 wholesale, according to data gathered by Connecture, a health insurance data specialist. Now it’s jumped to $365.16, an increase of 544.77 percent. Since the end of 2013, the price has gone up by 15 percent every other quarter.

EpiPens have become an important tool because they are so easy to use. They can be administered by the patient or a bystander by placing the pen on the patient’s middle outer thigh. While some emergency response agencies have responded to the high cost by discontinuing the use of EpiPens in favor of vials and syringes, the pens are still a source of assurance to the people who suffer from life-threatening allergic reactions.

The actual cost to consumers of an auto-injection device like the EpiPen is subject to a variety of factors, particularly the user’s insurance coverage. Also, consumers may be able to save a good deal of money by opting for generic alternatives.

As of 22 August 2016, two senior members of the U.S. Senate’s Judiciary Committee, senators Chuck Grassley and Amy Klobuchar, have inquired with Mylan about the price spike and urged the Federal Trade Commission to investigate whether the company violated antitrust laws.