Drug-Food Interactions

Foods to avoid or be careful with when taking common medications

This is for educational purposes only

Always consult your pharmacist or doctor about specific food interactions with your medications. This list covers common interactions but is not exhaustive.

Statins (e.g. Atorvastatin, Simvastatin)

Avoid

Avoid / Watch

Grapefruit and grapefruit juice

Why

Grapefruit inhibits the CYP3A4 enzyme that metabolizes statins, leading to dangerously elevated drug levels in your blood. This increases risk of muscle damage (rhabdomyolysis) and liver injury.

Alternatives / Advice

Oranges, lemons, limes, and other citrus fruits are safe. Pravastatin and rosuvastatin are less affected by grapefruit.

Blood Thinners (Warfarin / Coumadin)

Moderate

Avoid / Watch

Foods high in Vitamin K (kale, spinach, broccoli, Brussels sprouts)

Why

Vitamin K promotes blood clotting and directly counteracts warfarin. Sudden changes in vitamin K intake can make your INR levels unpredictable.

Alternatives / Advice

You don't have to avoid these foods entirely — just keep your intake consistent from week to week so your dose stays calibrated.

MAOIs (e.g. Phenelzine, Tranylcypromine)

Dangerous

Avoid / Watch

Tyramine-rich foods: aged cheese, cured meats, soy sauce, draft beer, fermented foods, red wine

Why

MAOIs prevent the breakdown of tyramine, which can cause a sudden, dangerous spike in blood pressure (hypertensive crisis) that may lead to stroke.

Alternatives / Advice

Fresh (non-aged) cheeses, fresh meats, and non-fermented foods are generally safe. Always carry your MAOI diet card.

Thyroid Medications (Levothyroxine / Synthroid)

Timing

Avoid / Watch

Calcium-rich foods (milk, yogurt), iron supplements, soy products, coffee

Why

These foods and supplements bind to levothyroxine in the stomach, reducing absorption by up to 40%. This means you're not getting your full dose.

Alternatives / Advice

Take levothyroxine on an empty stomach, 30-60 minutes before eating. Wait at least 4 hours before taking calcium or iron supplements.

ACE Inhibitors (e.g. Lisinopril, Ramipril)

Moderate

Avoid / Watch

High-potassium foods in excess: bananas, oranges, potatoes, tomatoes, salt substitutes

Why

ACE inhibitors cause your body to retain potassium. Combined with high-potassium foods, this can lead to hyperkalemia — a dangerous condition that can affect heart rhythm.

Alternatives / Advice

You don't need to eliminate these foods, but limit intake and avoid potassium-based salt substitutes. Have your potassium levels checked regularly.

Tetracyclines (e.g. Doxycycline, Minocycline)

Avoid

Avoid / Watch

Dairy products: milk, cheese, yogurt, ice cream

Why

Calcium in dairy binds to tetracycline antibiotics and forms insoluble complexes, reducing absorption by 50-65%. This can make the antibiotic ineffective.

Alternatives / Advice

Take tetracyclines 1 hour before or 2 hours after dairy. Calcium-fortified juices should also be avoided around dose time.

Metformin (Glucophage)

Moderate

Avoid / Watch

Excessive alcohol

Why

Both metformin and alcohol independently increase the risk of lactic acidosis — a rare but life-threatening condition. Alcohol also impairs blood sugar regulation.

Alternatives / Advice

Moderate alcohol may be acceptable for some patients — discuss limits with your doctor. Never drink alcohol on an empty stomach while on metformin.

Want to check if your specific medications interact with each other?

Drug Interaction Checker