Fortune 500 rank: 212
2007 loss: $1.47 billion
Drugs are a blockbuster business. So when Schering-Plough's patent on allergy medication Claritin expired in 2003, the company needed to do something dramatic. It got a new CEO and launched a restructuring plan, which culminated with last year's $16 billion acquisition of European drugmaker Organon BioSciences.
Schering took a $4 billion charge related to the deal, which tanked earnings. But 2008 may not be much better: Vytorin, a cholesterol drug combination from Schering-Plough and Merck, is under fire from lawmakers who say the companies misrepresented its effectiveness. NEXT: Sovereign Bancorp