A company can grow organically or through mergers and acquisitions. Catamaran (CTRX), formerly called SXC Health Solutions, is taking the latter route. In July, the company wrapped up its $4.4 billion buyout of rival Catalyst Health Solutions. The completion not only prompted a name change, but also created the fourth-largest pharmacy benefits management company (PBM) by prescription volume. PBMs handle drug benefits for health plans, employers