Foods and Pharmaceuticals That Don’t Mix

Even fruits and vegetables can cause strange and unsafe interactions with prescription medicines

Photo Modified: Flickr / Pablo Docal / CC BY 4.0

Foods and Pharmaceuticals That Don’t Mix

drugs alcohol

Photo Modified: Flickr / Pablo Docal / CC BY 4.0

Whether you are experiencing a minor infection or a serious health problem, doctors typically prescribe prescription drugs to treat the conditions and improve your health. Although you should be eating nutritious foods to keep you healthy during the period when you're taking the medication (just as you do all the time), high amounts of vitamin-rich foods can react in unexpected ways with drugs.

What Are ACE Inhibitors?

What Are ACE Inhibitors?

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ACE inhibitors, such as captopril, enalapril, and lisinopril, are used to lower blood pressure or prevent heart failure. They can also be used to reduce fluid retention in the body.

Mixing Bananas with ACE Inhibitors


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ACE inhibitors can increase the amount of potassium in the body. Bananas, which contain a lot of potassium, can cause irregular heartbeat and heart palpitations in combination with the ACE inhibitors, according to Consumer Reports.

ACE Inhibitors: Avoid High Potassium Foods

oranges banans

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Not just bananas but oranges and leafy green vegetables contain large amounts of potassium.

What Are Blood Thinners?


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Blood thinners are typically recommended to people who have heart or blood vessel disease or poor blood flow to the brain, according to Medicine Plus, or who are prone to atrial fibrilation.

Mixing Kale with Blood Thinners


Combining blood thinners with kale, which is rich in vitamin K, can reduce the drug’s anti-clotting effects.

Blood Thinners: Avoid Vitamin K- Rich Foods


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Foods such as kale, broccoli, cabbage, spinach, and Brussels sprouts are rich in vitamin K. Eating greens is important part of a healthy diet but you may want to discuss the risks with your doctor before combining them with blood thinners.

What Is Digoxin?


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Digoxin (Lanoxin) is used to treat heart failure and irregular heart rhythms.

Mixing Black Licorice with Digoxin

black licorice

Black licorice contains glycyrrhizin, which can cause irregular heartbeat or death when combined with digoxin. Glycyrrhizin has also been shown to make everything from blood pressure medications and blood thinners to pain relievers and birth control pills less effective.

Digoxin: Avoid Licorice Extract


Candy that is licorice flavored is not as harmful as the real licorice extract. If you take a licorice-root supplement for heartburn, you want to also be aware to avoid this.

What is Tetracycline?

What is Tetracycline?

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Tetracycline is an antibiotic used to treat several different kinds of bacterial infections, such as urinary tract infections, acne, gonorrhea, chlamydia, and others, according to

Mixing Tetracycline Antibiotics with Milk


The calcium found in milk can prevent the body from absorbing antibiotics, such as tetracycline.

Tetracycline Antibiotics: Avoid Calcium-Rich Foods


Milk, yogurt, cheese, and calcium supplements can prevent antibiotics from being effective. This antibiotic also should be taken one or two hours after eating, according to Consumer Reports.

What Are Cholesterol Drugs?


Common cholesterol drugs, such as atorvastatin and lovastatin, are used to reduce symptoms of high cholesterol.

Mixing Cholesterol Drugs with Grapefruit Juice

grapefruit juice

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Drinking grapefruit juice in combination with cholesterol drugs can increase the levels of the drug in the bloodstream and create a higher risk of experiencing side effects, such as leg pain.

Cholesterol Drugs: Avoid Grapefruit


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Grapefruit and grapefruit juice have been known to interfere with other drugs as well, so be sure to consult with your doctor before mixing the two.

What Is Metronidazole and Linezolid?


Metronidazole and linezolid are drugs that are used to treat bacterial infections. 

Mixing Metronidazole and Linezolid with Salami


Salami contains the amino acid tyramine, which can spike your blood pressure, when eating in combination with these drugs.

Metronidazole and Linezolid: Avoid Tyramine


Foods that are aged, pickled, fermented, or smoked, such as processed cheese, sausage, and anchovies contain amounts of tyramine. Tyramine can also be found in avocados, bananas, chocolate, and alcoholic beverages.

What Are Thyroid Drugs?

thyroid drugs

Thyroid drugs, such as levothyroxine, are used to help the thyroid regulate properly.

Mixing Thyroid Drugs with Walnuts


Consuming walnuts with thyroid drugs can prevent the body from absorbing medications. 

Thyroid Drugs: Avoid High Fiber Foods

soybean flour

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Although fiber is an important part of a healthy diet, foods such as walnuts, soybean flour, cottonseed meal, and other high-fiber foods can prevent the medication from working effectively. If you eat a lot of high fiber foods, you may need a higher dose.

Other: Mixing Drugs and Alcohol

drugs alcohol

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Drinking alcohol can make you feel drowsy, light-headed, and less coordinated than usual, but mixing alcohol with drugs can enhance those side effects. Alcohol can also make drugs less effective or worse, it can make a drug toxic, so be sure to check the label for warning.

Other: Mixing Drugs and Supplements


Some supplements such as vitamins, minerals, and herbals can negate the effects of some prescription  drugs. Surprisingly, the natural herb St. John’s wort can cause serotonin syndrome when combined with antidepressants or migraine drugs. This syndrome could affect the blood pressure and lead to death. 

Be Open With Your Doctor and Pharmacist



When you are prescribed a medication, be sure to list all of the supplements and drugs you take, so that they can advise you on which foods to include or not include in your diet.