Rowen is a clinical pharmacist by training, and geriatrics is his area of specialization. From 1994 to 1998, he served as director of pharmacy services at the James F. Byrnes Center for Geriatric Medicine, Education, and Research and the William S. Hall Psychiatric Institute, South Carolina Department of Mental Health. He has also served as a clinical pharmacist in geriatric medicine at the WJB Dorn Veterans Administration Hospital in Columbia, and was a consultant and owner of  Pharmacare in Irmo, S.C. Rowen’s experience as a practicing pharmacist included serving as clinical pharmacist in internal medicine at Richland Memorial Hospital in Columbia; hospital pharmacist, Department of Pharmacy, New Hampshire Hospital, Concord, N.H.; pharmacy manager and pharmacist, Rite Aid Corporation, Wilmington, Del.; and pharmacy technician, Inman Square Pharmacy, Cambridge, Mass.

Rowen is a member of the South Carolina Geriatrics Society and served on its board of directors from 2006-2008; he is active in the American Association of Colleges of Pharmacy and serves on the Administrative House of Delegates. His other professional memberships include the American College of Clinical Pharmacy; American Geriatrics Society, Clinical Practice Committee 2006-2009; American Society of Health-System Pharmacists; South Carolina Society of Health-System Pharmacists and South Carolina Pharmacy Association.

Rowen has received many honors and awards, including membership in Phi Lambda Sigma, Pharmacy Leadership Society, Zeta Chapter; Upjohn Pharmacy Research Award, South Carolina Society of Hospital Pharmacists; Research Certificate of Scientific Merit, Southern Medical Society Annual Meeting; and Rho Chi Honor Society, Beta Tau Chapter, Northeastern University. Rowen has made presentations throughout the country to organizations such as the American Psychiatric Association, California Pharmaceutical Association, American Academy of Family Practitioners, Southern Medical Society, American College of Physicians and the Research Society on Alcoholism. Rowen has been published in Pharmacotherapy, Hospital Therapy, the American Journal of Hypertension, the Journal of Clinical Geropsychology; and many other peer-reviewed journals.