Nutrition Connection: Food and Supplements Can Interfere With Medications

(reprinted from Nutrition & Foodservice Edge, March 2012)

Do you feel confident identifying potential foods or dietary supplements that might interact with medications?  Is this part of your quarterly review, or do you hope someone else will note the potential food, dietary supplement, or medication interactions?

Do you know which residents take vitamin and mineral and herbal supplements? Do you know which residents consume beer, wine, or liquor on a daily basis? When do residents usually take medications?

Back to Basics: How Medications React in the Body
To understand food-dietary supplements-medication interactions, it’s important to understand how medications work in the body. There are four stages of medication action for medicines taken by mouth:

Stage 1. The medication dissolves into a useable form in the stomach or small intestine.

Stage 2. The medication is absorbed into the blood and transported to its site of action.

Stage 3. The medication performs the function for which it is taken.

Stage 4. The medication is excreted from the body either by the kidney or the liver, or both.

While not all medications are taken by mouth, they are all transported to the site of action. Since medications taken by mouth dissolve in the stomach or small intestine, the presence of food, beverages, or dietary supplements may interfere with the action of the medication.

Food and Medication Interactions
Components of foods, beverages, and dietary supplements consumed at the same time as medications can interfere with the way medicine is supposed to work. These interactions can occur with both prescription and over-the-counter medications, including dietary supplements and herbal supplements. Risk for food-dietary supplement-medication interactions can be affected by many factors such as:

• Age
• Medical history
• Body composition
• Nutritional status
• Number of medications used

Residents often take medications right before a meal or with a meal. Some medications are taken with food to prevent stomach irritation. Even if medications are given between meals, residents may take them with food provided by staff or families. While some of the foods associated with medication interactions are found on the menu, many are brought in by well-meaning friends and family. Common consequences of food-dietary supplement-medication interactions include:

• Delayed action of the drug
• Decreased effectiveness of the drug
• Enhanced absorption of the drug
• Increased excretion of the drug
• Faster metabolism of the drug
• Impaired nutrient utilization

Taking Action
Make a commitment to identify residents who might experience food-dietary supplement-medication interactions. All medications, dietary supplements, and routine alcohol intake should be noted on the physician orders. Identify residents who consume alcohol on a daily basis. Table 1 summarizes examples of common medication interactions with food and beverages.

Dietary Supplements and Medication Interactions
Identify residents who take dietary and herbal supplements daily. Many residents take a multiple vitamin and mineral supplement daily that provides the RDA for these nutrients. These products are rarely of concern. It is the high dose single nutrient supplements and herbal products that may interact with medications. Table 2 summarizes common interactions between dietary supplements and medications.

Pearls for Practice
Identifying and avoiding food, dietary supplement and medication interactions take an ongoing team effort. Educate families and frequent visitors about potential food-dietary supplement-medication interactions. Work collaboratively with the RD, physician, pharmacist, and families to ensure that residents are receiving quality care.

Table 1: Common Medication Interactions with Food and Beverages

Table 2: Common Interactions Between Dietary Supplements and Medications

References
1. Pronsky, Zm. Food Medication Interactions. 16th Edition. Birchrunville, PA. 2010.
2. McCabe, B.J., Frankel, E.H., Wolfe, J.J., eds. Handbook of Food-Drug Interactions. CRC Press, Boca Raton, FL. 2003.
3. Akamine, D., Filho M.K., & Peres, C.M. Drug-nutrient interactions in elderly people. Current Opinion in Clinical Nutrition
and Metabolic Care, 10:304-310, 2007.
4. Genser, D. Food and drug interaction: Consequences for the nutrition/health status. Annals of Nutrition & Metabolism
52(suppl 1):29-32, 2008.
5. McCabe, B.J. Prevention of food-drug interactions with special emphasis on older adults. Current Opinion in Clinical Nutrition and Metabolic Care, 7:21-26, 2004.
6. Important Drug and Food Information. NIH Clinical Center. http://www.cc.nih.gov/ccc/patient_education/important_
drug_info.html. Accessed 2/12/12.
7. Food + Drug Interactions. National Consumers League. http://www.nclnet.org/health/146-food-drug-interactions/442-
avoid-food-drug-interactions. Accessed 2/11/12.

by Mary Litchford, PhD, RD, LDN

Mary Litchford, PhD, RD, LDN is a nationally-recognized speaker and the author of various articles and books, including Common Denominators of Declining Nutritional Status.