According to pharmaceutical market research giant IMS Health, global pharma sales grew 5.1% to $956 billion between 2010 and 2011. This represented an all-time high and was nearly double the level of $503 billion back in 2003. Growth has slowed from closer to 9% annually roughly a decade ago, but continues to advance at a very healthy clip. Below is an overview of five of the best-selling individual drugs of all time.