Glenn Saldanha, Glenmark's chief executive, said "the 10% was the cost of consolidation, which every single pharma company is taking if it has to continue holding its market share". The president of the company's North American operations, Robert Matsuk, however, believes the worst may be over. In the US, drug distributors, also referred to as pharmacy benefit managers (PBMs) – CVS Caremark, Cardinal Health and AmerisourceBergen – purchase drugs from manufacturers, and sell them to retail drugstore chains like Walgreen, Alliance Boots, Rite Aid and Shoppers Drug Mart. Since 2012, there has been extensive consolidation between pharmacy managers and retail chains –16 mergers and acquisitions were reported in 2012 and 10 in the following year. This included CVS Caremark, the largest supplier of prescription drugs in the US, acquiring Coram, a specialty infusion service provider, for $2.1 billion.