Health Notes

AVOIDING FOOD/DRUG INTERACTIONS
What you eat and drink can affect the way your medicines work. This information from the US Food and Drug Administration (“FDA”) addresses interactions between some common medications (prescription and over-thecounter [“OTC”]) and food, caffeine and/or alcohol. This
article only answers common questions and discusses the most common food-drug interactions; it does not replace conversations with your doctor or pharmacist about your specific medical conditions and specific medications…

WHAT’S A FOOD-DRUG INTERACTION?
According to the FDA, a food-drug interaction is a change in how a medicine works when combined with food, caffeine or alcohol. A food-drug interaction can…

  • prevent a medicine from working the way it should cause a current side effect from a medicine to change (get worse or improve…)
  • cause a new side effect
  • change the way your body uses a food

Any of these changes can be harmful, and should be reported to your doctor or pharmacist, so they can be monitored, and medicines can be changed (change in dose of current medicine, or replaced by a different medicine).

WHAT ELSE AFFECTS HOW MY MEDICINES WORK?
Your age, weight, and sex; your medical conditions; the dose of the medicine; other medicines (including vitamins, herbals and other dietary supplements can affect how your medicines work. Every time you use a medicine, carefully read the label and warnings, and follow the instructions given by your doctor or pharmacist.

DOES IT MATTER IF I TAKE A MEDICINE ON A FULL OR EMPTY STOMACH?
Yes, with some medicines – some medicines can work faster, slower, better or worse, when you take them with or without food. Some medicines can cause stomach upset, and taking them with food reduces this problem. Some medicines will not be properly absorbed if taken when food is in your stomach – these medicines must be taken on an “empty stomach” and the medicine bottles label should include instructions, for example, “take one hour before eating, or two hours after eating”. Other medicines will include instructions to “take with food”.

CAN I TAKE MY MEDICINES WITH ALCOHOL?
Not wise….The way your medicine works can change if...

  • you swallow your medicine with alcohol
  • you drink alcohol after you’ve taken your medicine
  • you take your medicine after you’ve had alcoholic drinks

Alcohol can also add to the side effects caused by medicines. You should talk to your doctor about alcohol you use or plan to use.

HOW DO I KNOW IF CAFFEINE IS IN MY FOOD OR DRINKS?
Some foods and drinks with caffeine are coffee, colas or other soft drinks, teas, chocolate, and some high-energy drinks. For more information about caffeine, go to www.fda.gov/downloads/UCM200805.pdf

FIVE COMMON FOOD-DRUG INTERACTIONS

  • Grapefruit and grapefruit juice has the ability to interact with several medicines in various ways, causing the body to metabolize drugs abnormally, resulting in lower or higher than normal blood levels of the drug: these include “statins” (cholesterol-lowering drugs), antihistamines, blood pressure drugs, thyroid replacement drugs, birth control, stomach acid-blocking drugs, and the cough suppressant dextromethorphan.
  • Leafy green vegetables can decrease the ability of blood-thinners such as warfarin (Coumadin®) to prevent clotting because of the vitamin K in the dark green leaves. NOTE: you don’t have to give up greens altogether: problems arise from significantly or suddenly increasing or decreasing green vegetable intake, as it alters the medicine effects – just eat your greens in consistent amounts!
  • Natural black licorice contains an ingredient called glycyrrhiza which can deplete the body of potassium and causing retention of sodium. This can affect the activity of digoxin, a medication used to treat heart failure, as well as blood pressure meds and the blood-thinner warfarin. NOTE: artificially-flavored black licorice doesn’t contain glycyrrhiza and is okay!
  • Salt substitutes must be used with caution in people taking digoxin for heart failure or ACE inhibitors for high blood pressure. Most salt substitutes replace sodium with potassium, which decreases the effectiveness of these medications. Also, persons with decreased kidney function should discuss the use of salt substitutes with their doctors.
  • Tyramine-containing foods can result in a dangerous increase in blood pressure in people taking monoamine oxidase inhibitors (“MAOIs”) which treat depression, and drugs used to treat symptoms of Parkinson’s disease. The list of these foods is lengthy – some (not all!) are aged and mature cheeses, chocolate, smoked/aged/fermented meats, hot dogs, fermented soy products, draft beers (canned and bottled beers are okay…)
 

When receiving a new prescription or taking a new over-the-counter drug, always read the drug warning labels and ask your doctor or pharmacist which foods or other drugs to avoid, or what problems might occur that must be reported to the doctor…

 

“Avoid Food-Drug Interactions: A Guide from the National Consumers League and US FDA”

Reprinted by Permission by Marla Lichtsinn, RN, MPA, FCN, Parish Nurse