u.s. senator chuck grassley ask department defense department veterans affairs tuesday explain spend trend epipen emergency allergy treatment request follow recent report reuters detail epipen price hike manufacturer mylan nv add millions u.s. department defense spend since 2008 agency cover prescriptions lifesaving allergy shoot near retail price know price increase epipens hit individual consumers medicare medicaid grassley republican say statement need determine whether taxpayers overpay epipen department defense va whether deserve rebate medicaid spend warrant squeeze health care budget mylan agree last month pay 465 million settle question whether underpay u.s. government healthcare program misclassifying epipen company raise price package two epipens sixfold 600 last decade senator grassley ask defense department explain epipen spend