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Certain medications, foods just don’t mix
Spinach is a powerhouse vegetable, filled with antioxidants and nutrients.
But the healthful, leafy green may not beneficial for people taking blood thinners.
According to the U.S. Food and Drug Administration, spinach and other food high in vitamin K — such as broccoli, brussels sprouts, green leaf lettuce, cauliflower and kale — can block the effects of anticoagulants such as Coumadin.
“These foods can be eaten, but in moderation, perhaps just once a week or so,” said Bob Karetsky, director of pharmacy services at Good Samaritan Regional Medical Center.
According to pharmacist Fred Haley, director of pharmacy services at Pottsville Hospital and Warne Clinic, food can interact with both prescription and over-the-counter medications, including vitamins, supplements, herbal remedies, antacids and iron pills.
“Things that you might not even be aware of, like drinking a glass of milk with antibiotics, can make a difference in how the medication works,” Haley said.
Dairy products, like milk, yogurt and cheese, have been found to inhibit the infection-fighting effects of antibiotics.
And although drug information is routinely provided with prescriptions, included with warning labels for over-the-counter medicines and offered by physicians and pharmacists, sometimes it goes unheeded, Karetsky said.
“Things can get tricky, especially when a person is taking several meds at once,” he said.
Unpleasant and dangerous side effects, a loss in the medication’s absorption and effectiveness and nutritional problems can occur, he said.
Some food nutrients can affect the way the body metabolizes certain drugs by binding with the medication’s ingredients and reducing their absorption or speeding their elimination. A glass of orange juice, for example, may decrease the effectiveness of antibiotics.
According to the FDA, grapefruit juice should be avoided while taking a variety of medications — including certain blood pressure or cholesterol-lowering drugs, HIV medications, organ-transplant drugs, hormones, antihistamines, antibiotics and sedatives — because of potentially dangerous side effects.
A study by researchers at the Mayo Clinic has found that, unlike other citrus juices, grapefruit juice inhibits one of the body’s intestinal enzyme systems and can result in marked increases in serum levels of some prescription drugs, raising blood concentrations of the drug beyond what the dosage calls for.
MAO inhibitors, commonly used to treat depression, can have a dangerous and potentially fatal interaction when mixed or taken with food or drinks that contain the amino acid tyramine, a chemical found in alcoholic beverages like beer and red wine and in some foods such as nuts, sauerkraut, pickles, olives, fermented soy products like soy sauce and teriyaki, hard cheeses, chocolate and beef or chicken livers.
Not all medications are affected by food, but many can be affected by when you eat it, according to Karetsky.
Diuretics, also called “water pills,” help eliminate water, sodium and chloride from the body and can vary in their interactions with food and specific nutrients.
Some diuretics can cause loss of potassium, calcium and magnesium and supplements are often recommended to avoid nutritional deficits.
The diuretic triamterene, however, is a potassium-sparing diuretic, which blocks the kidneys’ excretion of potassium. This can cause hyperkalemia, or increased potassium in the body, resulting in irregular heartbeat and heart palpitations.
Those taking triamterene should avoid eating large amounts of potassium-rich foods such as bananas, oranges and green, leafy vegetables or salt substitutes that contain potassium.
Sometimes, taking medications at the same time you eat may interfere with the way your stomach and intestines absorb medication.
Antihistamines are used to relieve the symptoms of colds, hay fever, and allergies by limiting or blocking histamine, a substance released by the body when it’s exposed to allergens. According to the FDA, it’s usually best to take prescription antihistamines on an empty stomach.
Anti-inflammatories, like aspirin, can irritate the stomach, so they usually should be taken with food.