Tips to avoid unwanted interactions

There's a lot to pay attention to when you're managing medications for yourself or someone else—including knowing what foods and drugs may cause adverse side effects. Interactions between certain food and medications can be dangerous, so it’s always important to talk to your doctor about your diet or any changes in prescriptions. Listed below are some common medications and the foods that may cause adverse interactions.1

Monoamine oxidase inhibitors (MAOIs) for depression mixed with tyramine

MAOIs were the first type of antidepressant developed. There are four types of MAOIs approved by the Food and Drug Association (FDA): Isocarboxazid (Marplan), Phenelzine (Nardil), Selegiline (Emsam) and Tranylcypromine (Parnate). When taking MAOIs be careful to avoid foods with tyramine. Foods with tyramine include:

  • aged cheese
  • chianti wines
  • chicken liver
  • venison
  • sauerkraut
  • aged sausages like pepperoni and salami

Taking MAOIs with foods that contain tyramine may cause extremely high blood pressure, fever and, in rare circumstances, death.2

Blood thinners and leafy greens

Taking medications that contain warfarin, an anticoagulant, in combination with large portions of foods high in vitamin K can potentially decrease the effectiveness of warfarin and increase the risk of blood clots. A few examples of foods with high amounts of vitamin K are:3

  • spinach
  • turnip greens
  • broccoli

Alcohol with medications

Drinking alcohol while taking large doses of acetaminophen-containing products, such as Tylenol®, may cause liver damage. Drinking alcohol while taking metronidazole to treat infections may result in flushing, vomiting and increased heart rate.

Various medications and grapefruit

Studies have shown that mixing certain medications with grapefruit or grapefruit juice can cause dangerously high levels of those medications in the blood, which may cause potentially life-threatening side effects.3 These medications include those used to treat depression, arrhythmia, transplants, seizures, high blood pressure and high cholesterol.

Antibiotics and osteoporosis medications with calcium

Taking osteoporosis medications and certain antibiotics along with calcium-fortified foods and drinks such as milk, orange juice, bread or antacids may reduce the effectiveness of these medications. Try to take your medication 2 hours before or 4 hours after consuming calcium-rich food and drinks.

Aspirin and an empty stomach

Aspirin and other over-the-counter pain medications taken without food can cause stomach bleeding.


  1. “MAOIS and diet: Is it necessary to restrict tyramine?” Mayo Clinic, last accessed July 7, 2023, , opens new window
  2. “Warfarin and Other Blood Thinners for Heart Disease,” WebMD, last accessed July 7, 2023, , opens new window
  3. “Patient’s Guide to Taking Warfarin,” American Heart Association, last accessed July 7, 2023, , opens new window
  4. “Grapefruit Juice and Some Drugs Don’t Mix,” U.S. Food and Drug Administration, last accessed July 7, 2023, , opens new window

This material is intended for informational use only and should not be construed as medical advice or used in place of consulting a licensed medical professional. You should consult with your doctor.

Explore more medication articles