Heart Medicines: Taking Them Safely

Many people have problems with their heart and blood vessels. These problems include atrial fibrillation, coronary artery disease, heart failure, high cholesterol, and high blood pressure.

If you have any of these problems, you most likely take many heart (cardiac) medicines.

These medicines help your symptoms and can prevent your heart problem from getting worse. But they also may interact with other medicines.

What is a drug interaction?

A drug interaction happens when a medicine you take changes how another medicine works.

One medicine may make another one not work as well. Or you may get a side effect you don't expect.

Some reactions can be dangerous.

Medicines, vitamins, herb supplements, and even some foods may affect the way a medicine works in your body.

You are more likely to have a drug interaction if you:

  • Have many health problems, or you have a health problem that is not stable (is changing).
  • Are an older adult. As you age, your body handles medicine differently. Your kidneys and liver process some medicines more slowly. As your muscle mass and body fat change, some medicines stay in your body longer.
  • Take high doses of medicines.
  • Take medicines that your body processes in the same way (through your kidneys or liver).
  • Take a lot of medicines. The more you take, the higher the chances of unwanted side effects.

What medicines cause problems?

  • Warfarin (Coumadin) and other blood thinners interact with many medicines. Be sure all of your doctors know that you take a blood thinner. And talk to your doctor before you take any new medicines or supplements. These include prescription or over-the-counter medicine, vitamins, minerals, and diet supplements.
  • Digoxin with beta-blockers or calcium channel blockers. This combination can slow the heart too much and may make your heart problem worse. A brand name for digoxin is Lanoxin.
  • Nitrates and medicines for erections. If you are using nitrates, do not take an erection-enhancing medicine. Your blood pressure may drop to a dangerous level if you take both types of medicine. Nitroglycerin and isosorbide dinitrate are nitrates. Erection medicines include sildenafil, tadalafil, and vardenafil.
  • ACE inhibitors, angiotensin II receptor blockers (ARBs), prescribed potassium, and other medicines. ACE inhibitors or ARBs can raise potassium levels. Tell your doctor if you are taking potassium pills or vitamins that have potassium. ACE inhibitors or ARBs also may interact with NSAIDs, antacids, diuretics, and lithium. ACE inhibitors include benazepril, enalapril, and lisinopril. ARBs include candesartan, irbesartan, and losartan.
  • Statins and other medicines. Taking statins with some other medicines may cause side effects you do not expect. Statins include atorvastatin, lovastatin, pravastatin, and simvastatin. Tell your doctor about all the medicines you take. These include other cholesterol medicines, heart medicines, antibiotics, medicines that weaken your immune system, and medicines that treat fungal infections.

What about herbs and other supplements?

Herbs and other supplements also interact with medicines. Below are some better-known herbs and how they might interact with medicines.

  • Black cohosh may lower blood pressure when you take it with some medicines.
  • Ginkgo biloba may increase bleeding when you use it with aspirin or some other blood thinner. It may raise blood pressure when you use it with some diuretics.

What can you do to help prevent an interaction?

Here are some things you can do to help prevent an interaction:

  • Know your medicines. Ask your doctor what your medicines do and why you are taking them. Ask if there are interactions you should look out for and what to do if you think something is wrong. Be sure all your doctors know that you take medicine for a heart problem.
  • Ask about drug interaction checkers. Some doctors and pharmacies can put your medicine list through a computer database to check for bad interactions. If you find a problem, talk to your doctor.
  • Go to one drugstore to buy your medicines. The pharmacist will know which medicines you are taking and watch for interactions.
  • Let your doctor know all the medicines you are taking. Make a list for your doctor that has each medicine's name, purpose, strength, dose, and directions. Or bring your medicines with you when you see your doctor. Be sure to bring all supplements, herbs, vitamins, and minerals you are taking. Your doctor needs to see the ingredients on a supplement label to know if it can cause a reaction.

Do not take any herbs or other supplements without talking with your doctor first.