(Reuters) - U.S. Senator Chuck Grassley asked the Department of Defense and the Department of Veterans Affairs on Tuesday to explain spending trends for the EpiPen emergency allergy treatment.

The request followed a recent report by Reuters detailing how EpiPen price hikes by manufacturer Mylan NV had added millions to U.S. Department of Defense spending since 2008 as the agency covered more prescriptions for the lifesaving allergy shot at near retail prices.

"We know the price increase for EpiPens is hitting individual consumers and Medicare and Medicaid,” Grassley, a Republican, said in a statement. “We need to determine whether taxpayers overpaid for the EpiPen through the Department of Defense and the VA and whether they deserve a rebate, as they do with Medicaid. Spending that isn’t warranted squeezes the health care budget.”

Mylan agreed last month to pay $465 million to settle questions of whether it underpaid U.S. government healthcare programs by misclassifying EpiPen.

The company raised the price for a package of two EpiPens by sixfold to more than $600 over the last decade.

(Reporting By Deena Beasley; Editing by Andrew Hay)