Some medications just don’t mix with certain foods (and drinks). Bananas, milk, kale, grapefruit juice, walnuts, bacon, black licorice, chocolate, and mozzarella can be delicious treats on their own, but when combined with certain prescription drugs, they can cause new side effects, worsen existing side effects, affect how your medications work, and even change the way your body uses food. Combining medications with alcohol or caffeine can have unwanted consequences and should typically be avoided. Of course, always consult your doctor and pharmacist about prescription drug information and instructions. If you or a member of your family is taking prescription drugs to lower blood pressure, treat heart failure, Parkinson’s disease, depression, or osteoporosis, it is important to be informed about food-drug interactions and which foods to avoid when taking certain medications.

Black Licorice and Fiber

Medicine Type: Glycosides
Example: Digoxin

Glycosides are a type of medication used to treat various heart conditions. Eating black licorice or other sweets that contain glycyrrhizin in combination with the drug digoxin can cause an irregular heart beat and heart attack. Digoxin also doesn’t work well with high-fiber foods which can decrease the digoxin in your body. In order for the drug to work best, fiber-rich foods like raspberries, bran, spaghetti, beans, lentils, artichokes, and split peas should be eaten at least two hours before or two hours after taking digoxin.

Grapefruit Juice

Medicine Type: Lipid-Altering Agents (Statins)
Examples: Atorvastatin, Fluvastatin, Lovastatin, Pravastatin, Simvastatin, Rosuvastatin

Statins are a class of drug that can help lower cholesterol levels in the blood to help prevent heart attacks and stroke. Drinking grapefruit juice with some of these types of medications may increase the amount of the drug in the body, potentially causing harmful side effects. Seville oranges, pomelos, and tangelos may have the same effect as grapefruit juice. It is advised to not drink more than one quart of grapefruit juice a day if you are taking atorvastatin, lovastatin, or simvastatin.

Mineral Water

Medicine Type: Bisphosphonates (Bone Calcium Phosphorus Metabolism)
Examples: Alendronate Sodium, Alendronate Sodium + Cholecalciferol, Ibandronate Sodium, Risedronate Sodium, Risedronate Sodium + Calcium Carbonate

Bisphosphonates are commonly prescribed drugs used to treat osteoporosis, osteopenia, Paget’s disease, certain bone cancers, and similar diseases to help prevent the loss of bone mass. This drug should only be taken with plain water, not mineral water, tea, coffee, or fruit juice which can interfere with their absorption. Absorption is substantially diminished when this drug type is given with meals, especially in the presence of calcium and iron. Therefore, bisphosphonates should never be given at mealtimes and never together with milk or dairy products.

Potassium

Medicine Type: ACE Inhibitors (Angiotensin Converting Enzyme Inhibitors)
Examples: Captopril, Enalapril, Lisinopril, Moexipril, Quinapril, Ramipril

Medicine Type: Diuretics
Examples: 
Bumetanide, Furosemide, Hydrochlorothiazide

Too much potassium in the body is harmful and some drugs may cause higher than normal potassium levels resulting in hyperkalemia. Symptoms include an irregular heartbeat, heart palpitations, weakness, nausea, dizziness, and low blood pressure. ACE inhibitors are drugs used primarily for the treatment of hypertension and congestive heart failure and can increase potassium levels. Some diuretics can reduce potassium minerals levels, and others, like triamterene (not with hydrochlorothiazide), can lower the kidneys’ ability to remove potassium. Therefore, when taking these types of medications, you may need to avoid overeating potassium-rich foods like bananas, oranges, watermelon, beets, spinach, sweet potatoes, yogurt, tomato paste, canned white beans, and salt substitutes with potassium.

Vitamin K, Cranberry Juice, and Garlic

Medicine Type: Vitamin K Agonists/ Anticoagulants
Example: Warfarin

Anticoagulants, like warfarin, are blood thinners used to treat and prevent blood clots that might result in heart attack, stroke, or death. A significant change in your intake of vitamin K from food can make the medicine less effective. Therefore, your doctor may recommend that you eat a consistent diet of vitamin K-rich foods without increasing or decreasing your daily amount. Vitamin K is used by the body to help blood clot. Foods high in vitamin K include soybean and canola oils, spinach, broccoli, cabbage, collard greens, kale, turnip greens, and Brussels sprouts.

Cranberry juice taken with anticoagulants may also interfere with blood thinners. A considerable amount of blood-thinning salicylic acid is found in this fruit and may raise the risk of bleeding. Some studies recommend avoiding significant amounts of garlic, ginger, glucosamine, ginseng, and ginkgo because they can increase the chance of bleeding. Your doctor will be able to talk to you about the best diet for your needs while taking these medications.

Soybean Flour

Medicine Type: Thyroid Medicines
Example: Levothyroxine

Thyroid medicines can be used to treat hypothyroidism, a condition when an under-active thyroid can’t make enough of the thyroid hormone. Talk to your doctor about your diet and learn if you need to avoid taking your thyroid medication with soybean flour, walnuts, cotton seed meal, and fiber as some studies believe it may interfere with the body’s ability to absorb the medication.

Tyramine

Medicine Type: Psychiatric Disorders: Antidepressants-Monoamine Oxidase Inhibitors (MAOIs)
Examples: Phenelzine, Tranylcypromine

Monoamine oxidase inhibitors (MAOIs) are medications prescribed for the treatment of depression. MAOIs block an enzyme known as monoamine oxidase which breaks down excess tyramine in the body, thereby leading to higher levels of tyramine in the body. Avoid foods and drinks that contain tyramine when you use MAOIs to keep tyramine levels low. High levels of tyramine can cause a sudden, dangerous increase in your blood pressure. Tyramine is often found in aged and fermented foods, such as in some aged cheeses including blue cheese, brie, parmesan, mozzarella, cheddar, American, and gorgonzola, smoked fish, cured meats, dry sausage (including Genoa salami, hard salami, pepperoni, and Lebanon bologna), caviar, dried or pickled herring, anchovies, meat extracts, meat tenderizers and meats prepared with tenderizers, overripe fruit, canned figs, fava beans, sour cream, yogurt, soy sauce, soybean condiments, miso soup, sauerkraut, yeast extract, and draft beer plus it can be found in avocados, bananas, dried fruits (raisins, prunes), chocolate, and raspberries.

Dairy Products and Tyramine

Medicine Type: Antibacterials (Infections)
Quinolone Antibacterials Examples: Ciprofloxacin, Levofloxacin, Moxifloxacin
Tetracycline Antibacterials Examples: Doxycycline, Minocycline, Tetracycline
Oxazolidinone Antibacterials Example: Linezolid
Metronidazole Antibacterials Example: Metronidazole

Antibacterial medications, also called antibiotics, are used in the treatment and prevention of bacterial infections. Some antibiotics, like tetracycline and ciprofloxacin, have certain restrictions on being taken with dairy products like milk, cheese, ice cream, and yogurt. This is because the calcium in these products decreases absorption of the medication making it less effective. Your doctor may recommend that you avoid consuming dairy products and calcium-fortified juices up to two hours or more before or after you take your medication.

Linezolid is another medication that should not be taken with foods containing tyramine. This antibiotic can cause an elevation in blood pressure. Because tyramine can also raise blood pressure it is important to limit tyramine-rich foods and drinks. See above for Tyramine-containing foods to avoid.

Histamine and Tyramine

Medicine Type: Antimycobacterials
Examples: Ethambutol, Isoniazid, Rifampin, Rifampin + Isoniazid Rifampin + Isoniazid + Pyrazinamide

Antimicrobial drugs are used to treat mycobacterial infections such as tuberculosis (TB) and leprosy. Avoid foods and drinks with tyramine and foods with histamine if you take isoniazid alone or combined with other antimicrobials. See above for tyramine-containing foods to avoid. The combination of antimicrobials and foods with histamine can cause headaches, sweating, rapid heartbeats, flushing, and low blood pressure. Histamine-rich foods include smoked fish and certain species of fish including mackerel, mahi-mahi, tuna, anchovies, sardines and skipjack, fermented alcoholic beverages, many aged cheeses, fermented and pickled foods, vinegar-containing foods, sour foods, some dried fruits, citrus fruits, nuts, and vegetables like avocados, eggplant, spinach, and tomatoes.

Source: US Food and Drug Administration (FDA) https://www.fda.gov