Antibiotics + Dairy
Antibiotics in the quinolone family, such as Cipro and Levaquin, bind to calcium and iron, so avoid dairy and supplements containing iron—foods won’t contain enough iron to be a problem—when taking these medications, says Jeff McClusky, pharmacy supervisor with the Harris Health System in Houston, Texas, and American Pharmacy Association spokesman. By blocking the drugs’ absorption, these products could make the antibiotics ineffective, leaving your infection untreated. Make sure you always ask these 12 questions before taking antibiotics.
Blood Thinners + Lettuce
Vitamin K, found in high amounts in such foods as kale, lettuce, broccoli, and chickpeas, could be a threat to those on the blood thinner warfarin. Fluctuations in your levels of vitamin K can inactivate warfarin, says Howard Weintraub, MD, clinical director of the New York University Center for the Prevention of Cardiovascular Disease. Try eating consistent amounts of vitamin K-containing foods each week; but always check with your doctors. Here are 10 more important questions to ask before filling a prescription.
Blood Pressure Medication + Licorice
Licorice contains glycyrrhizian, which raises blood pressure, says Dennis Goodman, MD, a clinical associate professor at New York University. Taking it with medications meant to lower blood pressure can reduce the drugs’ effectiveness and leave blood pressure dangerously high, he says. (Don't miss these other 10 mistakes that could make OTC medications unsafe.) Other foods that might interfere: People on ACE inhibitors might consider salt substitutes to reduce their sodium intake, but some such as the brand Nu-Salt contain high amounts of the mineral potassium, says Dr. Weintraub. Paired with the potassium-raising effects of ACE inhibitors, you could have too-high levels of the mineral, he continues, which could possibly even cause cardiac arrest. Pomegranate seeds can also amplify an ACE inhibitor’s effects, causing lightheadedness or dizziness from overly low blood pressure. Again, check with your doctors with any questions. Plus, ask your physician about these 10 things to know about taking too many medications.
Statins + Grapefruit Juice
Grapefruit juice inhibits the enzyme system your body uses to metabolize these cholesterol-lowering drugs, which means they might not work as well. (Check out these other 6 benefits and 2 dangers of grapefruit.) It’s important to avoid the juice altogether, not just at the time you take your medication, says McClusky. Find out how to know if you take too many medications.
MAO inhibitors + Aged Cheeses
This class of antidepressants blocks a key enzyme that helps break down tyramine, an amino acid found in aged cheese as well as very ripe bananas, beer, avocado, cured meats, and spinach. Tyramine can raise blood pressure if not broken down, so when people on MAO inhibitors consume these foods, they could experience a potentially fatal rise in blood pressure that could cause severe chest pain, clamminess, and sweating, says Annelle Primm, MD, deputy medical director of the American Psychiatric Association. (Don't miss these other 11 signs your medication is making you sick.) Avoid other stimulants too—including caffeine—as they can amplify the effects of the drug, Dr. Weintraub adds. Many psychiatrists avoid prescribing MAO inhibitors now, in part because of their strict dietary requirements, but some doctors use them to treat patients in the early stages of Parkinson’s disease. Don't miss these other 34 secrets pharmacists aren't telling you.
Certain Chemotherapy + Orange Juice
Without an exact dose of the chemotherapy drug etoposide, the medicine might not be able to inhibit cancer cells' growth, says McClusky. Cranberry juice and orange juice can block the absorption of the drug if taken at the same time, so make sure to use a glass of water to wash down your medicine, then wait half an hour before pouring your morning OJ. During treatment, stick with these 11 best foods to eat during chemotherapy.