For the past 15 years, Mr Holmes worked for Omnicare, a provider of pharmaceutical care for the elderly, and served most recently as vice president of operations.
Prior to joining Omnicare, Mr Holmes was executive vice president for Healthcare Prescription Services, a long-term care pharmacy located in Indianapolis.
Gregory Weishar, CEO of PharMerica, said: “Denis brings considerable experience to our company. His 20-year career encompasses all aspects of the institutional pharmacy business. He is a great addition to our management team.”