Expert Health Articles

Common Food-Drug Interactions

Jacqueline Boucher, PA-CJacqueline Boucher, PA-C

Caughman Health Center Pediatrics 

Taking medicine is a normal routine for many people, but there are many aspects to think about to avoid unwanted interactions. Age, weight, sex, medical conditions, dose of medicine, other medications, vitamins and herbal supplements can affect any drug taken. Some drugs can work faster, slower, better or worse on an empty stomach while others will upset an empty stomach. Alcohol also has significant effects on medication use. Drinking alcohol while taking medication, or before and after, can affect how the drug works in the body.

When a food affects medications in the body, this is called food-drug interaction. Food can prevent medicine from working the way it should and can cause medicinal side effects to become better or worse and/or cause new side effects to occur. Drugs can also change the way the body uses food. There are a variety of food and drug interactions that can occur, but here is a small list of common drugs and how food affects the way they are used in the body. 

  • Green, leafy vegetables, which are high in vitamin K, can decrease how well aspirin thins the blood. Consuming the same amount of green-leafy vegetables each day will decrease this interaction.
  • Grapefruit juice alters the way the body absorbs statins (cholesterol-lowering drugs) like Lipitor in the blood. It can cause these drugs to be absorbed in higher than normal amounts resulting in a greater risk of side effects.
  • Calcium channel blockers are prescribed for high blood pressure and are also affected by grapefruit juice. Grapefruit juice changes the way this drug breaks down in the body and may cause overly high levels of the drug in the blood, raising the risk of side effects. 
  • Dairy products such as milk, yogurt and cheese decrease the absorption of antibiotics. Try to eat meals one to two hours before taking these to avoid this interaction.
  • Alcohol affects insulin or oral diabetic pills. Alcohol prolongs the effects of these drugs, which leads to low blood sugar.
  • Moderate pain reliever drugs with acetaminophen should not be taken with alcohol because it has a higher chance of causing severe liver damage. Antihistamines, like Benadryl, should not be taken with alcohol because it will cause increased drowsiness.

This is only a small list of drugs that are affected by food, but it is important to be informed about common medications that are consumed. Most medications and over-the-counter drugs have warnings stating when it is ok and when it is not ok to consume them, so do not be alarmed about taking any current medications. Doctors and pharmacists are always available to answer questions.