SAN FRANCISCO — Mark Walchirk has been named president of McKesson U.S. Pharmaceutical, the largest operating unit of McKesson Corp.

Walchirk, who was most recently chief operating officer of McKesson Specialty Health, has held numerous leadership roles at the company for the last 11 years, including that of chief operating officer of McKesson U.S. Pharmaceutical. He succeeds Brian Tyler, who was recently appointed executive vice president of corporate strategy and business development at McKesson Corp.

Walchirk will oversee McKesson’s largest business, which supplies branded, generic and over-the-counter pharmaceuticals and business, clinical and connectivity solutions to over 40,000 customers, including retail chains, independent retail pharmacies, hospitals, health systems, integrated delivery networks and long-term care providers.

“With past roles as chief operating officer of McKesson U.S. Pharmaceutical and McKesson Specialty Health, Mark has deep leadership experience in our pharmaceutical distribution business and a record of delivering results for our customers,” said Paul Julian, executive vice president and group president at McKesson Corp. “Mark’s significant experience coupled with his commitment to operational excellence and our customers’ success make him the ideal choice to lead McKesson U.S. Pharmaceutical.”

Walchirk joined McKesson in 2001 and spent more than eight years in progressive leadership roles within its U.S. pharmaceutical business before being appointed president of McKesson Specialty Care Solutions in 2009. He led McKesson’s integration of US Oncology and assumed the role of chief operating officer for the newly combined organization, McKesson Specialty Health. In this role he helped lead the business to record growth and introduced new solutions that empower the community patient care delivery system.

As senior vice president and chief operating officer of McKesson U.S. Pharmaceutical, Walchirk led the integration of regional distributors D&K Healthcare and McQueary Bros.; contributed to the growth of McKesson’s Health Mart franchise; led the expansion of McKesson’s pharmaceutical distribution business in the institutional market; and guided McKesson to industry-leading levels of accuracy and efficiency across the company’s nationwide distribution network.

Before joining McKesson, Walchirk spent 13 years in the medical-surgical distribution and manufacturing sectors.

Separately, McKesson announced it is acquiring MedVentive, a provider of population and risk management tools that drive transparency in health care cost and quality.

MedVentive’s solutions are expected to augment McKesson’s capabilities and experience to support providers. Based in Waltham, Mass., MedVentive serves health systems, multi­specialty clinics and payers nationwide. Its solutions and services should be strong additions to the McKesson Enterprise Intelligence suite of solutions to help health care organizations understand and manage the quality, cost and efficiency of providing patient care.

“More health care providers are beginning to assume risk as we move to value-based reimbursement,” said Pat Blake, who serves as executive vice president and group president of McKesson Technology Solutions. “Whether it’s for their employee population, a Medicare shared savings plan or a defined disease state group, providers must understand the risk they are assuming. What providers really need — and McKesson’s solutions will help offer — is a true picture of the total cost of delivered care based on clinical documentation and claims data across all care ­settings.”