Food and Drug Interactions You Need to Know About

Don't Mix With

The Reason

ACE inhibitors such as captopril (Capoten), enalapril (Vasotec), and lisinopril (Prinivil, Zestril), used to lower blood pressure or treat heart failure. And avoid mixing with some diuretics, such as triamterene (Dyrenium), used to reduce fluid retention and treat high blood pressure.

These foods are all high in potassium, which helps provide electrical signals to heart-muscle cells and other cells. Consuming them with the medications listed to the left could increase the amount of potassium in your body and may lead to an irregular heartbeat or heart palpitations—which could be deadly.

Blood thinners such as warfarin (Coumadin).

Foods that contain a lot of vitamin K, such as the greens noted on the left, can reduce the drugs’ ability to thin the blood. In some people with heart disease, that could trigger a heart attack or a stroke. Once you begin taking warfarin, maintain a consistent diet and don’t suddenly overload on leafy greens.

Digoxin (Lanoxin), used to treat heart failure and abnormal heart rhythms. It’s also best not to consume with most blood pressure drugs, blood thinners, and birth-control pills.

Real black licorice (and products with licorice extract, as opposed to licorice-flavored candy) contain glycyrrhizin, which can cause an irregular heartbeat, or even death, when combined with digoxin. Glycyrrhizin may reduce the effectiveness of most blood pressure drugs, intensify the side effects of blood thinners, and raise blood pressure and lower potassium levels when consumed with birth-control pills.

Tetracycline.

The calcium in these foods and products can interfere with the body’s ability to absorb the antibiotic fully. In general, tetracycline works better if taken 1 hour before or 2 hours after eating.

Drugs such as metronidazole (Flagyl) and linezolid (Zyvox), used to treat bacterial infections.

The foods to the left, along with tap beer, red wine, and sherry, contain tyramine, an amino acid that can cause blood pressure to spike if taken with linezolid. Tyramine is also found in foods that are aged, pickled, fermented, or smoked, such as processed cheeses, anchovies, and dry sausage. Alcohol and metronidazole together could cause nausea, stomach cramping, and vomiting.

Thyroid drugs such as levothyroxine (Levothroid, Levoxyl, Synthroid).

These high-fiber foods can prevent your body from absorbing the medications. If you eat a high-fiber diet, try taking your medications later in the evening. One study found that the drugs were better absorbed when taken at bedtime rather than a half-hour before breakfast, which is what is usu­­ally recommended in the instructions.