Silver Book Fact
Increased use of multiple prescription medications has been shown to raise the risk of adverse drug interactions for older adults. The risk of injury is associated with the use of 9 or more prescription medications or the ingestion of 12 or more medication doses a day.
Warshaw G. Introduction: Advances and challenges in care of older people with chronic illness. San Francisco, CA: American Society on Aging; 2006:5-10. http://www.ingentaconnect.com/content/asag/gen/2006/00000030/00000003/art00002