On November 30th Pfizer's patent on Lipitor expired.  Since 1997 it has earned the pharmaceutical giant $81 billion, and the title of best-selling prescription drug of all time.  But now, Ranbaxy has released a generic version: Atorvastatin. While some generic medications can function somewhat differently than their brand-name counterparts, all projections for Atorvastin are predicting that it will be a good alternative.  Most prescription drug plans have now added Atorvastatin to their list of covered drugs.  Read more about the story here.