Food, Juice, and Drugs: Hold the Grapefruit
Do your patients know about the interactions between common foods and drugs?
When it comes to other food and medication interactions, there is also some confusion, Plogsted said. Patients taking anticoagulants may be confused about which vegetables are the leafy green ones—even when given a list of the vegetables to avoid. The message that needs to be heard by these patients is to not change their daily eating habits once blood levels have stabilized, Plogsted said. If they eat broccoli twice a week and everything is stable, they should not change the routine, he explained. Kaefer asks patients about what vegetables they usually eat and explains that they can have some broccoli or Brussels sprouts as long as they are consistent about it. “Don’t suddenly go on an all-salad diet if you don’t ever eat salad,” she said.
Instructions like “take with food” or “take on an empty stomach” may also be open to wrong interpretations, Plogsted added. The gold standard advice for taking a medication on an empty stomach is to avoid taking the drug for one hour before a meal or two hours afterward, he said, but this may not be helpful for people who eat several small meals during the day or don’t eat at the times a medication needs to be taken.
One food and drug interaction now seen less commonly is between MAOIs and foods high in the amino acid tyramine, Kaefer noted. MAOIs are being used less often, but patients taking these drugs should be counseled to avoid cured meats and aged cheeses, among other foods.
Another food and medication issue is potassium intake with ACE inhibitors in elderly patients, both Kaefer and Plogsted said. Patients who may have compromised kidneys must be counseled to avoid high-potassium foods and especially to avoid salt substitutes that contain high levels of potassium. “Grapefruit juice gets all the press and green leafy vegetables with warfarin gets a lot press. But people don’t pay much attention to potassium with the ACE inhibitors.”
1. American Pharmacists Association. Juice interactions: What patients need to know. Available at https://www.pharmacist.com/juice-interactions-what-patients-need-know. Accessed on Jan. 24, 2017.