Medicare fears haunt drug stocks By: MarketWatch August 04, 2011 at 16:02 PM EDT Concerns that the U.S. government could pare back Medicare reimbursements for prescription drugs are haunting drug stocks this week. Read More >> Related Stocks: Astrazeneca Plc ADR Novo Nordisk A/S ADR Pfizer Sanofi-Aventis S.A. ADR Standard & Poors 500 Vertex Pharmaceuticals