Whether you are driving your car, truck, SUV, RV, or motorcycle, riding your bike or merely walking, you share the road with other vehicles, drivers, and pedestrians. You cannot control them, and they may not always “stay in their lane.” Similarly, medications that we swallow can have the same dilemma with foods and drinks that we consume. After all, they share the same route of transit: mouth, esophagus, stomach, and intestines. There are no designated lanes, and, consequently, medications may be affected by food. “Food-drug” interactions describe when foods affect a drug’s: —Absorption. Delays digestion or binds to the drug and decreases absorption. Alternatively, foods may accelerate drug absorption.
—Metabolism. Increases or decreases the breakdown
—Excretion. Alters the kidney’s ability to clear the drug from the body
—Effects. Changes the way it works, causes a new side effect, or causes a worsening of a side effect What You Need to Know about fruit, vegetables, and drinks that can interact with commonly prescribed medications.
Bronchodilators: Opens and relaxes the air passages of the lungs to relieve wheezing and shortness of breath. They are typically prescribed to those with a diagnosis of asthma, emphysema, or chronic bronchitis. Using bronchodilators with foods and drinks that have caffeine can increase the risk of side effects: excitability, nervousness, and a fast heartbeat. Caffeine is not just found in coffee and sodas, but also teas, chocolate, and energy drinks.
ACE Inhibitors: Lowers blood pressure and treats heart failure. One of the side effects of these medications is that they can increase the amount of potassium in your body. When potassium levels become too high, palpitations and dangerous heart rhythms can result. To that extent, it is wise to avoid large amounts of food that are high in potassium: bananas, oranges, green leafy vegetables, and salt substitutes.
Coumadin: Blood thinners for conditions such as atrial fibrillation, blood clots (deep vein thrombosis, pulmonary embolus), and certain conditions of the blood that predispose to clots. Because these are serious conditions, we want the blood-thinning effects of coumadin to be effective. However, foods that are rich in Vitamin K can decrease its ability to prevent clots from forming. These include “greens” such as broccoli, cabbage, spinach, kale, and brussel sprouts.
Statins: Lowers high-density lipid (HDL) cholesterol. Recently, new guidelines were released that may mean 1 in 3 Americans will soon be taking a statin. If you take this med, make sure you avoid eating grapefruit or drinking grapefruit juice around the time you take the pill. This fruit contains an enzyme that can raise the level of the drug in your blood stream and increase the risk of side effects. The enzyme can also affect metabolism (the breakdown) of antihistamines, blood pressure drugs, thyroid replacement drugs, birth control, and stomach acid-blocking drugs.
Thyroid replacement drugs: Supplements thyroid hormone in those who cannot produce enough. However, foods that are rich in fiber can prevent your body from absorbing thyroid medications, leaving the drug
under-effective or ineffective.
Prescribed medications contain a “Medication Guide,” also known as a Med Guide. It is specifically written for patients to inform us of risks associated with the drugs we are taking and how to avoid them.
Before taking any new prescription, make sure to carefully read the Med Guide and information on the label to look for foods to avoid. If you have any questions, speak with your doctor or pharmacist. It may not be necessary to completely avoid the food, but to cut back or wait a few hours to indulge (which allows the drug to have its own lane).
Additionally, medications may work faster, slower, better, or worse depending if they are taken on a full or empty stomach. An “empty stomach” is often defined as two hours after eating and one hour before eating. Some medications were not meant to share the road with foods.
Medications are powerful agents that can help us live healthier and longer lives. It is important to take them as prescribed and pay attention to the “rules of the road.”
Bacon and chocolate. Chili and peanut butter. Some unlikely combinations end up working well together. But when it comes to diet and drugs, the wrong pairing can unwittingly turn into a recipe for disaster. You don’t need a prescription to face these risks—even some common over-the-counter treatments should warrant more careful
attention to your menu, says Jen Wolfe, Pharm.D., a D.C.-based pharmacist and consultant with Comprehensive Pharmacy Consulting.
Here are seven dangerous duos to dodge
1. Limes and cough medicine.
You may have heard not to drink grapefruit juice with some prescriptions, including cholesterol-lowering statins. But limes, pomelos, and Seville oranges—although not the more-common navel and Valencia varieties—also may block an enzyme that breaks down statins and other drugs, including the cough suppressant dextromethorphan.
Because the medication then builds up in your bloodstream, the risk for side effects increases, says Mary Ellen Gullickson, Pharm.D., a pharmacist at Marshfield Clinic in Wisconsin. With dextromethorphan, this includes hallucinations and sleepiness; in statins, you may sustain severe muscle damage. These fruits’ effects can linger for a day or longer, so it’s best to avoid them and their juices altogether while taking these drugs. And if you’re a citrus fiend? Check in with your pharmacist about potential drug interactions, Gullickson recommends.
2. Dairy products and antibiotics.
Some antibiotics, including Cipro, bind to calcium, iron, and other minerals in milk-based foods. “This prevents the absorption of the antibiotics, ultimately decreasing their ability to fight infections,” Gullickson says. When you get a new prescription for acne or an infection, ask if the drug falls into a class known as tetracyclines or flouroquinolones. If so, avoid milk, yogurt, and cheese 2 hours before and after taking the pills. And talk with your pharmacist about
proper timing if you take multivitamins with minerals — they can have a similar effect, Gullickson says.
3. Smoked meats and antidepressants.
Check the label on these meds. If they belong to a class called monoamine oxidase inhibitors or MAOIs—brand names Marplan, Nardil, Emsam, or Parnate—combining them with foods rich in the amino acid tyramine can cause life-threatening spikes in blood pressure, says Gullickson. Unfortunately, the list of no-nos includes not only summer sausage and smoked salmon, but also red wine, sauerkraut, hot dogs, aged cheeses, soy sauce, and draft or home-brewed beer. The good news?
Canned or bottled beer probably won’t hurt you—and MAOIs have largely been replaced by newer-generation antidepressants, which don’t have the same effect on tyramine levels, says Nicole Gattas, Pharm.D., B.C.P.S., assistant professor of pharmacy practice at St. Louis College of Pharmacy.
4. Chocolate and Ritalin.
Besides caffeine, chocolate also contains a stimulant called theobromine, says Tom Wheeler, Pharm.D., B.C.P.S., director of pharmacy and pulmonary services at Advocate Illinois Masonic Medical Center in Chicago. (It’s the reason chocolate harms dogs — canine bodies can’t break it down.) Combining all these stimulants in humans
can potentially lead to erratic behavior and seizures. As with caffeine alone, the risks are largely individual. Your best bet: Take note of whether you feel more nervous, irritable, or wired when you combine Ritalin — especially the extended-release forms—with chocolate. If so, increase the amount of time between downing your pill and having dessert. Or, lighten up: “The darker the chocolate, the more caffeine and theobromine it contains,” Wheeler says.
5. Apple juice and allergy meds.
Nix the nectar from apples, oranges, and grapefruits if you take Allegra (fexofenadine) for hay fever—at least within 4 hours of swallowing the pill, Gullickson advises. These juices inhibit a peptide that transports the drug from your gut to your bloodstream.
The resulting lack of absorption makes Allegra up to 70 percent less effective at stopping your sniffling and sneezing, Wheeler says. Other medications also travel with the help of the same peptide; lay off these juices while taking the antibiotics Cipro or Levaquin, the thyroid medication Synthroid, or the allergy and asthma treatment
Singulair, he says.
6. Cinnamon and warfarin.
People taking the blood-thinning medication warfarin—prescribed to prevent or treat clots—have long been warned to keep their intake of vitamin K steady, says Wolfe. This means you shouldn’t change your weekly intake of foods like leafy greens or broccoli; because vitamin K plays a key role in clotting; doing so could affect the thickness of your blood. But there’s another risk. Cassia cinnamon, the kind on most American grocery-store shelves, contains high levels of a compound called coumarin that can thin blood and potentially cause liver damage, says Eric Newman, M.D., a resident at Mercy Medical Center in Baltimore. If you’re on warfarin, switch to Ceylon cinnamon
instead, he advises. (Find it at gourmet or spice retailers like Penzeys, where it’s $11.29 for 4 ounces.)
7. Alcohol and acetaminophen.
Resist the urge to wash down your Tylenol with a cold one—your body uses the same enzyme to break down the two substances. It’s generally best to put six hours between drinking booze and taking any medicine containing acetaminophen, including over-the-counter and prescription pain and cold medicines, Gattas says. But the bigger risks come with time: “If you drink alcohol every day, it’s probably not a good idea to take Tylenol,” Wheeler says. Pairing them regularly can contribute to kidney and liver disease.
* * * * *
Dr. Nina Radcliff is dedicated to her profession, her patients and her community, at large. She is passionate about sharing truths for healthy, balanced living as well as wise preventive health measures.
She completed medical school and residency training at UCLA and has served on the medical faculty at The University of Pennsylvania. She is a Board Certified Anesthesiologist and a member of the American Society of Anesthesiologists where she serves on committees for Young Physicians and Communications. Author of more than 200 textbook chapters, research articles, medical opinions and reviews; she is often called upon by media to speak on medical, fitness, nutrition, and healthy lifestyle topics impacting our lives, today.