http://www.npr.org/sections/health-shots/2016/08/24/491232665/latest-target-in-the-drug-price-wars-the-ubiquitous-epipen?utm_campaign=KHN%3A+Daily+Health+Policy+Report&utm_source=hs_email&utm_medium=email&utm_content=33405785&_hsenc=p2ANqtz-8XZii4uOFohPHJzQb2tGya0B1V39hwW9G6vwptGGc5BvcM-YWZemfyDF8k4814h6RX0C21PHgcZ9Nz_LIAH_zmJW4gCw&_hsmi=33405785

The wholesale price of a single pen was about $47 in 2007, and it rose to $284 this summer, according to Richard Evans, a health care analyst at SSR. But consumers can no longer buy a single pen, so the retail price to fill a prescription today at Walgreens is about $633, according to GoodRX.

It’s the latest in a string of controversies over rising drug prices that have caught the attention of lawmakers on Capitol Hill.

The drug’s manufacturer, Mylan NV, responded to the criticism Thursday, announcing it will offer customers whose insurance doesn’t pay the full cost coupons for up to $300 off the injectors. But it’s unclear if that will be enough to tamp down the anger.

At least three senators have called for investigations into the price of the EpiPen, and Sens. Charles Grassley, R-Iowa, and Richard Blumenthal, D-Conn., have sent letters to Mylan demanding an explanation for the increase.