FDA Warns Biogen Idec, Inc. (Massachusetts), Sanofi-Aventis (France) on Tysabri, Plavix Promotional Links
NEW YORK, April 3 (Reuters) - The U.S. Food and Drug Administration sent warning letters to Biogen Idec Inc and Sanofi-Aventis about sponsored links on Internet search engines for their most important drugs that fail to provide required safety information.