How to stop Pfizer’s faux-Irish tax ripoff By: MarketWatch November 23, 2015 at 16:02 PM EST The U.S. Treasury is going after inversions, but drug companies’ vulnerability is Medicare, says Tim Mullaney. Read More >> Related Stocks: Alkermes Plc Allergan Plc Costco Wholesale Eli Lilly Jazz Pharma Plc Macy's Medtronic Perrigo Pfizer Valeant Pharmaceuticals International, Inc.