Herbal supplements and heart medicines may not mix
Many herbal supplements interact with medications for cardiovascular disease. Some of these interactions can be life-threatening.
By Mayo Clinic Staff
Herbal supplements are natural, so they must be safe, right? Not necessarily.
Herbal supplements can have strong effects in the body. Some can interact with prescription medications used to treat heart and circulatory problems, such as high blood pressure and heart failure. Some of these interactions can even be dangerous.
Herbal supplements and prescription medications
About one-half of adults in the United States report having used at least one dietary supplement in the previous month. But research suggests that only about 34 percent of people taking an herbal supplement tell their doctors about this use — and most of those people also are taking a prescription medication.
Yet many herbal supplements may interact with medications for cardiovascular disease. For example, several popular herbal supplements interact with the blood thinner warfarin (Coumadin, Jantoven).
Here are just a few of the herbal supplements that can affect warfarin:
- Danshen
- Licorice
- St. John's wort
There are several others. That's why it's so important to talk with your doctor before taking herbal supplements if you take prescription medications. Your doctor and pharmacist can help you avoid risky interactions.
Herbal supplements and drug interactions
Several popular herbal supplements interact with common heart medications. This list covers only some interactions. It's important to talk to your doctor before taking any herbal supplements if you take prescription medications.
Coenzyme Q-10
Taking coenzyme Q-10 can decrease:
- The effectiveness of warfarin
- Your blood pressure if you also take a calcium channel blocker, such as diltiazem (Cardizem, Dilacor XR, others)
Danshen
Danshen can interact strongly with certain heart medications, including:
- Anticoagulants. Taking danshen significantly increases your risk of bleeding if you also take warfarin or another anticoagulant, such as clopidogrel (Plavix) or aspirin.
- Calcium channel blockers. Taking danshen increases your risk of low blood pressure if you also take diltiazem or another calcium channel blocker.
- Digoxin (Lanoxin). Taking danshen increases the effects of digoxin — which is used to treat a variety of heart conditions — and puts you at risk of irregular heartbeat (arrhythmia).
Evening primrose
Evening primrose may increase your risk of bleeding if you also take an anticoagulant, such as:
- Aspirin
- Clopidogrel
- Warfarin
Garlic
Garlic increases your risk of bleeding if you also take an anticoagulant, such as:
- Aspirin
- Clopidogrel
- Warfarin
Gingko biloba
Ginkgo biloba increases your risk of bleeding if you also take:
- Aspirin
- Clopidogrel
- Warfarin
Ginseng
Taking ginseng with warfarin decreases warfarin's effectiveness.
Hawthorn
Hawthorn might interact with:
- Beta blockers, such as atenolol (Tenormin), nadolol (Corgard) or propranolol (Inderal LA, Innopran XL)
- Calcium channel blockers, such as diltiazem, nifedipine (Procardia) and verapamil (Calan, Verelan)
- Nitrates, such as nitroglycerin (Nitrostat, Nitro-Dur, others) and isosorbide (Dilatrate-SR, Isordil)
- Digoxin
Licorice
Licorice decreases levels of warfarin and can increase the effects of digoxin.
Saw palmetto
Saw palmetto increases your risk of bleeding if you also take:
- Aspirin
- Clopidogrel
- Warfarin
St. John's wort
Taking St. John's wort reduces the effectiveness of:
- Calcium channel blockers
- Digoxin
- Warfarin
- Statins, such as atorvastatin (Lipitor), lovastatin (Altoprev) and simvastatin (Zocor)
Playing it safe with herbal supplements
If your doctor tells you it's OK to use an herbal supplement combined with a medication, make sure you follow dosing instructions carefully. Watch for any unusual signs or symptoms that you could be having a drug interaction, such as:
- Rapid heartbeat
- Changes in blood pressure
Sept. 16, 2017
- Enioutina EY, et al. Herbal medicines: Challenges in the modern world. Part 5. Status and current directions of complementary and alternative medicine worldwide. Expert Review of Clinical Pharmacology. 2017;10:327.
- Saper RB. Overview of herbal medicines and dietary supplements. https://www.uptodate.com/contents/search. Accessed July 24, 2017.
- AskMayoExpert. St. John's wort. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2016.
- Geller AI, et al. Emergency department visits for adverse effects related to dietary supplements. New England Journal of Medicine. 2015;373:1531.
- Liperoti R, et al. Herbal medications in cardiovascular medicine. Journal of the American College of Cardiology. 2017;69:1188.
- Danshen. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed July 24, 2017.
- Licorice. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed July 24, 2017.
- AskMayoExpert. Dietary and herbal supplements. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2016.
- Coenzyme Q-10 Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed July 24, 2017.
- Evening primrose. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed July 24, 2017.
- Garlic. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed July 24, 2017.
- Gingko biloba. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed July 24, 2017.
- Hawthorn. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed July 24, 2017.
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