"A food-drug interaction is the alteration of a drug’s pharmacokinetics or pharmacodynamics when certain foods or beverages are consumed at the same time. Older patients are particularly at risk for negative food and drug interactions simply because this population takes more than 30% of all prescription drugs.1 Patients with cancer and/or malnutrition, gastrointestinal tract dysfunction, or acquired immunodeficiency syndrome; patients receiving enteral nutrition; and transplant recipients are also at risk."
http://www.todaysdietitian.com/newarchives/121610p26.shtml