HENRICO COUNTY, Va. -- As thousands of kids head back to school, Senator Mark Warner is questioning the manufacturer of the life-saving, EpiPen, which has seen a drastic price increase over the last few years.
The EpiPen is auto-injector that is potentially a life-saving treatment in the event of severe adverse allergic reaction. The pen injects a pre-measured dose of epinephrine to compact an allergic reaction from peanuts, eggs and other foods as well as bee stings and insect bites.
Since 2009, the price of the EpiPen has skyrocketed by nearly 500 percent. The device started at less than $60 a pen in 2007 and now costs $600 for a two-pack.
Sen. Warner pointed out, the EpiPen has no generic substitute on the market and is only manufactured by one pharmaceutical company, Mylan.

A Henrico grandmother says she is concerned about the drastic price hikes as her 11-year-old grandson has a severe allergic reaction to tree nuts.
"He pretty much knows what he can and can’t have,” said Mame Corcoran. "After eating peanut butter... he immediately got a rash and you know he's started having trouble.”
She said she knows how important the EpiPen can be and she can’t imagine not having one because of the $600 price tag.
“It seems to be the trend overall is to shifting people more to these high deductible plans and thus, patients get hit with these increased costs. They don’t realize it when they take out these plans,” said Dr. William Hark.
Dr. Hark with Richmond Allergy and Asthma Specialists says families can get discounts to offset the high deductibles, but they are still on the hook for the majority of the cost.
For uninsured patients, an EpiPen can cost as much as $734 out of pocket at a local pharmacy.

"I think a lot of patients out there... they're really worried about the kids. They just can't afford it and they just try and get by and hope for the best. Then, they may get in trouble and not have it when they need it,” said Dr. Hark.
CBS 6 checked in with area school systems who say the price increase won’t impact schools.
Richmond, Chesterfield, and Henrico schools say they have the EpiPens on hand through a free program with the drug maker Mylan.
School officials can also order more from the company at a discounted rate.
Here is Sen. Warner’s full letter to the CEO of Mylan.