Common Food and Drug Interactions.

Food-drug interactions should be suspected when a patient is taking their medications as directed and doses are optimized yet therapy is still not optimal (increased adverse effects, decreased efficacy, new adverse effects, etc). In all individuals with suspected food-drug interactions, diet history, baseline laboratory values, drug concentrations, and prescription history are recommended to assess the patient for a possible food-drug interaction. The 3 types of food-drug interactions are pharmaceutical, pharmacokinetic, and pharmacodynamic. Pharmaceutical interactions occur with delivery devices or enteral feeding products. Pharmacokinetic interactions include the processes of a drug's release, absorption, distribution, metabolism, and/or elimination, ultimately affecting the effectiveness and safety of therapy. Pharmacodynamic interactions occur when food alters a drug's clinical effect on the body. The most common food-drug interactions exist with fruits (especially grapefruit), dairy, vitamin K, tyramine-containing foods, and alcohol. Patient counseling and collaboration between health-care teams can help patients avoid food-drug interactions. As a result, medication therapy can be optimized and adverse effects can be avoided.