The biggest step in medication safety is surprisingly simple: filling the prescription and taking the medication. And yet, research indicates that more than 60% of cardiovascular patients don’t take their medication as prescribed.1 Failure to take medication properly is called nonadherence (or noncompliance). Nonadherence includes the following:

  • Never filling prescriptions
  • Not picking up prescriptions
  • Not starting the medications
  • Not following dosing instructions

Patients may use any number of common excuses for failing to take medication. Ultimately, no good excuses exist when your life is on the line. Among heart attack patients discharged from the hospital, those who filled none of their prescriptions within 120 days had 80% greater odds of death than those who filled all of their prescriptions.1 That's just one example.

If a medication makes you feel bad in any way or affects your ability to function as you normally would, DON’T stop taking it but DO tell your doctor. If you’re a cardiovascular patient, your medication serves both maintenance and prevention functions. Going off antiplatelet medication, for example, could allow blood to clot, causing a new heart attack or stroke. Medication is a critical part of your treatment, and your doctor will work with you to alleviate the side effects by adjusting the dosage or trying a different medication.

The most important thing to remember about medication is to take it as directed by your doctor or other healthcare provider. Even if you feel great, hear something negative about it on the news, or another doctor tells you to stop taking it before a procedure, check with your doctor first before you reduce or stop taking your medication.

Medication safety is best achieved through open and honest conversations between a doctor and patient. If, as a patient, you find challenges to taking your medication as prescribed or have concerns, discuss these with your doctor. Your doctor will use experience and professional expertise to recommend tools and suggestions to help you. Together, you can stay on track with taking prescribed medications, address any side effects, and prevent potentially harmful drug interactions.

Side effects

Trust your intuition: If a side effect seems serious, get help right away. However, do not stop taking a medication without consulting your doctor. You should make your doctor aware of any side effects that you’re experiencing. Many side effects are better than a cardiovascular event such as a heart attack or stroke. Contact a doctor right away if you’re experiencing serious side effects. Many of these will be listed on your medication information pamphlet or prescription bottle label, but you can learn more about side effects and interactions that have been associated with certain types of cardiovascular medications in the chart provided here.

Medication Type


Possible Side Effects, Interactions, and Special Instructions

ACE Inhibitors and ARBs

To lower blood pressure and allow blood to flow more easily from the heart

Dizziness, cough, and low blood pressure

Monitor kidney and potassium levels with blood tests


To control an irregular heartbeat

Side effects depend on the class of drugs

Calcium channel blockers can cause headaches and ankle swelling

Amiodarone can increase sensitivity to sunlight and affect eyesight

It may be important to monitor thyroid function and avoid grapefruit

Antiplatelet Medications

To thin the blood and help prevent and dissolve clots in arteries and stents

Stomach pain, headache, dizziness, and breathing difficulties

Side effects are more severe in patients with asthma and allergies

Take with food


To prevent and dissolve clots in the arteries

Stomach upset, headaches, and drowsiness

An allergic reaction could cause breathing difficulties

Other severe side effects include blood in the stool or coughing up blood

Take with food to reduce the risk of upset stomach

Beta Blockers

To lower blood pressure and heart rate

Dizziness, fatigue, dry mouth, slow heart rate, weight gain, erectile dysfunction, lack of libido, and cold hands and feet

Side effects may be reduced if taken with food

Clot Busters (Thrombolytics)

To restore blood flow during a heart attack or stroke and to break up blood clots in the legs (deep vein thrombosis)

Bleeding, abnormal heartbeat, and new clotting


To prevent blood clots from forming in the arteries and heart

Bleeding, vomiting or coughing up blood, blood in stool, headaches, and dizziness

Don't take aspirin unless directed by a doctor


To improve your heart's ability to pump blood and help to slow down an irregular heartbeat

Nausea, vomiting, diarrhea, stomach pain, loss of appetite, unusual tiredness, and slow heartbeat

Side effects are more common if too much is taken

Take on an empty stomach and eat high-fiber foods, which can decrease its absorption

Smoking Cessation Medication

To make it easier to stop smoking

Talk to your doctor to find the right fit for you


To lower your cholesterol level and reduce the risk of heart attacks and strokes

Muscle pain, liver damage, memory loss nausea, gas, diarrhea, constipation, and rash

Diuretics (Water Pills)

To lower blood pressure

Frequent urination, dehydration, blurred vision, fatigue, rash, and loss of appetite

Monitor blood pressure and kidney function


To widen the blood vessels to increase the flow of blood and lower blood pressure

Headaches, nausea, and dizziness, especially in older people

Don't drink grapefruit juice, as it may interact negatively with cold medicine

If you find yourself struggling with adhering to your medication plan for any reason, talk to your doctor. Don’t be embarrassed or worry about being scolded. Your safety is most important, and that means that you and your doctor must work together to find a solution.


Sometimes, researchers discover that certain drugs, foods, vitamin or herbal supplements, alcohol, and other medical conditions can affect one another and can make a medication less, or more, powerful than was intended or lead to other side effects.

Other times, patients don’t realize they need to tell their doctor about everything they’re taking, including over-the-counter medications, vitamins, herbal supplements, and hormone-based birth control. Forgetting to tell your doctor about supplements and medications, or feeling too embarrassed to do so, can have serious consequences. Be sure to talk with your cardiologist and primary care doctor about everything you’re taking and ask about possible interactions.

Potentially dangerous interactions

  • Hormone-based contraceptives – Birth control pills may place women* (assigned female at birth) at higher risk of high blood pressure and blood clots that can cause a stroke, a heart attack, clots in the legs, or a pulmonary embolism. Women that are over age 35, smokers, have high blood pressure, diabetes, or unhealthy cholesterol levels are most at risk. The birth control patch may pose an even greater risk because of its higher levels of estrogen. The connection between birth control pills and risk of heart disease remains unclear. If you have other risk factors, such as a history of heart disease in your family or if you’re a smoker, talk to your doctor about your concerns and options.
  • Erectile dysfunction (ED) medication – ED is fairly common among men* with heart disease, but if you have ED and are taking medication for it, it’s very important that you tell your doctor because if you have any of the following conditions, ED medications may not be advised:
    • Certain high-risk heart problems, including chest pain (angina), heart failure, abnormal heart rhythms (arrhythmias), or a recent heart attack (Note: ED medications shouldn't be taken with sublingual nitroglycerin pills or long-acting nitrates.)
    • Uncontrolled high or low blood pressure
    • A history of stroke within the last six months
    • Eye problems such as retinitis pigmentosa
    • Sickle cell anemia, leukemia, multiple myeloma, or another health problem that can cause an erection that won't subside (priapism)
  • Side effects from ED medications may include the following:
    • Headache
    • Flushing
    • Indigestion
    • Nausea
    • Stuffy or runny nose
    • Back pain and muscle aches (with Cialis)
    • Temporary vision changes (with Viagra)

It’s unlikely that you’ll have a serious side effect, but if you have a sudden loss of hearing or vision, or an erection that lasts longer than four hours, seek medical help immediately.

Drug databases

Several web databases provide information on drug interactions, but the best way to avoid dangerous interactions is to speak with your doctor and disclose all medications and supplements that you’re taking.

*The term “women” in the context of “women’s cardiovascular health” applies to individuals assigned female at birth (AFAB) who have a female biological reproductive system, which includes a vagina, uterus, ovaries, Fallopian tubes, accessory glands, and external genital organs.

*The term “men” in the context of “cardiovascular health” applies to individuals assigned male at birth (AMAB) who have a male biological reproductive system, which includes a penis, scrotum, testes, epididymis, vas deferens, prostate, and seminal vesicles.