The Norman Transcript

September 4, 2013

Concerns about food and drug interactions with medications

By Jessica Henderson MS, RD/LD
The Norman Transcript

NORMAN — Q: My elderly mother takes multiple medications for her many disease states. Recently, I overheard that there are many food/drug interactions. Should I be concerned?

 

A: For the most part, no. However there are a few common drug/nutrient interactions everyone should be aware of.

Grapefruit is the most commonly researched food that has been found to interact negatively with multiple medications. All in all, about 85 different medications have been shown to react with grapefruit. Statins, blood pressure medication and anti-clotting agents are among those drugs that have been found to have the most life-threatening interactions. Grapefruit contains an enzyme that prohibits our body from regulating the amount of drug in our systems which can lead to substantially more of the drug in our blood stream than recommended. This risk increases for those over the age of 70 as the body’s ability to regulate high concentrations of drugs decline with age. In addition to Statins, grapefruit it also commonly known to interact with zoloft, buspar, cyclosporine, allegra, plavix and certain immunosuppressants.

Vitamin K rich foods — People taking coumadin (warfarin) need to be aware that foods high in vitamin K may reduce the effect of their anticoagulant. It’s most important to consume a normal, balanced diet with steady amount of leafy, green vegetables in order to avoid these negative side affects. Consult your doctor before making radical dietary changes while on coumadin to get your blood levels tested.

Caffeine (coffee, tea, chocolate, etc) — Just be aware that caffeine can increase the side effects of certain medications such as bronchodilators and antipsychotics (clozapine).

Potassium — Foods that are high in potassium when combined with ACE inhibitors may boost potassium levels too high which can have adverse side effects.

Black licorice — The sweetening compound used in black licorice (glycyrrhizin) can cause irregular heart beat when combined with lanoxin (Digoxin). It also may reduce the effect of other blood pressure medications.

Foods rich in tyramine — Some foods high in tyramine such as picked foods, fermented foods and other aged foods can interact with some antibacterials, antimycobacterials and MAOI antidepressants.

Cranberry and cranberry juice should be avoided while using anticoagulants.

Alcohol — Avoid alcohol with any prescription drug as there is a long list of medications that have known interactions with alcohol including narcotics, Statins, asthma medications and many more. 

It’s also important to note that many supplements available off the counter have interactions with prescription drugs just as food does. It is important to be honest with you doctor about any and all supplements you are taking when being prescribed a new medication.

For nutritional counseling, Norman Regional Health System offers the guidance of registered dietitians. Those interested can schedule an appointment for an assessment with a referral from their family physician.