McKesson names Mark Walchirk president of U.S. pharmaceutical unit

Mark Walchirk.

McKesson Corp. named Mark Walchirk as president of its U.S. pharmaceutical unit, its largest business, effective immediately. He will be the unit's third president in the last 21 months. Walchirk, most recently COO of McKesson Specialty Health, has been with the San Francisco-based pharmaceutical distribution and health care information technology giant (NYSE: MCK) for 11 years. He succeeds Brian Tyler, who was named executive vice president of corporate strategy and business development of McKesson Corp. in late August.