Medical Disclaimer: MedSafe is for informational purposes ONLY. NOT a substitute for professional medical advice. Always consult your physician or pharmacist. In emergency, call 911.

Food & Drug Interaction Warnings

Certain foods can make your medication less effective — or even dangerous. Check what to avoid.

Common Food-Drug Interactions to Know

Warfarin

Grapefruit HIGH

May increase bleeding risk

Vitamin K foods (spinach, kale) HIGH

Reduces warfarin effectiveness

Alcohol HIGH

Increases bleeding risk

Cranberry juice MEDIUM

May increase bleeding

Metformin

Alcohol HIGH

Risk of lactic acidosis

Atorvastatin

Grapefruit juice HIGH

Increases statin levels — muscle damage risk

Alcohol MEDIUM

Increases liver damage risk

Levothyroxine

Calcium-rich foods MEDIUM

Reduces thyroid hormone absorption

Coffee MEDIUM

Reduces absorption — take 30min before coffee

Soy products MEDIUM

Interferes with absorption

High-fiber foods LOW

May reduce absorption

Ciprofloxacin

Dairy products MEDIUM

Reduces antibiotic absorption

Caffeine LOW

Increases caffeine effects

Sertraline

Alcohol HIGH

Increases depression/drowsiness

Grapefruit MEDIUM

May increase drug levels

Ibuprofen

Alcohol HIGH

Increases stomach bleeding risk

Take with food LOW

Reduces stomach upset

Doxycycline

Dairy products HIGH

Significantly reduces absorption

Antacids with calcium HIGH

Reduces antibiotic effect

Foods to Watch Out For

🍊 Grapefruit & Grapefruit Juice

Affects 85+ medications

Blocks the enzyme that breaks down drugs in your gut. Can cause overdose effects even with normal doses.

Affected drugs: Statins, Calcium Channel Blockers, Immunosuppressants, Some Antibiotics

🍷 Alcohol

Affects 150+ medications

Increases drowsiness, can cause dangerous blood pressure drops, liver damage, and stomach bleeding.

Affected drugs: Metronidazole, Blood Thinners, NSAIDs, Antidepressants, Sleep Medications

🥛 Dairy & Calcium-Rich Foods

Reduces absorption

Calcium binds to certain antibiotics and thyroid medications, reducing how much your body absorbs.

Affected drugs: Doxycycline, Ciprofloxacin, Levothyroxine, Bisphosphonates

🥬 Vitamin K Foods (Leafy Greens)

Reduces blood thinner effect

Spinach, kale, and broccoli contain Vitamin K which directly counteracts blood thinner medications.

Affected drugs: Warfarin (Coumadin), Acenocoumarol

☕ Caffeine & Coffee

Drug interaction risk

Can increase side effects of stimulants or reduce absorption of thyroid medications.

Affected drugs: Levothyroxine, Stimulants, Ephedrine, Theophylline

🫐 Cranberry Juice

May increase bleeding

Contains compounds that may boost the blood-thinning effect of warfarin.

Affected drugs: Warfarin, Aspirin