CHD Medications

Medicines are often needed to treat congenital heart defects until the defect can be repaired or corrected. Some complex acyanotic heart defects and most cyanotic heart defects require ongoing treatment with medicines even after the defect is repaired. Children with certain defects that cannot be completely corrected may have to take medicines for a long time.

Medicines used to improve blood flow and help manage symptoms related to heart failure include the following:


Furosemide (Lasix), as well as Capozide and Aldactone, are types of diuretics that cause the kidneys to remove water and salt (sodium) from the body. This reduces the amount of fluid in the body & lungs, lowers blood pressure, and helps the heart beat stronger. Because these medicines increase urination, diuretics are commonly called “water pills.”

In children who have congenital heart defects, diuretics often are given to treat symptoms of hypertension and heart failure (such as shortness of breath). Diuretics allow the heart to function more efficiently, which helps improve swelling and breathing difficulty.

Cardiac Glycosides/Inotropic Drugs

Digoxin is a type of cardiac glycoside that slows and strengthens the heartbeat by affecting the natural electrical system of the heart. Cardiac Glycosides most often are used to treat severe heart failure and atrial fibrillation that can occur with congenital heart defects. These conditions are more common in complex defects. It sometimes takes several weeks to determine the correct dose of this medicine. This medication is most often taken as pills, but is available in liquid form. Cardiac Glycosides help control rapid irregular heartbeats, reduce the backup of blood and fluid in the body (cause of swelling in the arms/legs and difficulty breathing), increase blood flow through the kidneys (helps get rid of sodium) and relieves swelling in the tissues of the body.


Captopril and Enalapril are types of vasodilators that treat heart failure in children with congenital heart defects. Vasodilator medicines decrease blood pressure by relaxing the muscle around the blood vessels. This allows blood vessels to expand, letting blood flow through the vessels and to the tissues of the body more easily.


Amiodarone, Adenosine, Beta Blockers, Calcium Channel Blockers, and Digoxin are types of antiarrhythmic medicines that are used to treat and prevent irregular heartbeats. They act on the electrical system of the heart and block some of the extra electrical activity in the cells of the heart. This makes the heart beat regularly. These medicines help control irregular heartbeats; they do not treat the congenital heart defect itself.

Other medicines may include:

Antibiotics before dental and surgical procedures, to help prevent endocarditis (in certain cases).

Anticoagulants to prevent blood clots after surgery. They are not always needed after surgery. If an anticoagulant is needed, a simple medicine may be prescribed, such as a daily aspirin, or a stronger medicine, such as Warfarin.

Beta Blockers are used to treat a variety or medical problems from hypertension, angina, arryythmias, heart failure, and myocardial infarct to migraine headaches and benign tremors.

Prostaglandins and Prostaglandin Inhibitors, to help keep open or to close the Ductus Arteriosus. Normally, a blood vessel needed only for fetal blood circulation (called the ductus arteriosus) closes off at birth. During fetal development, this blood vessel is kept open by a naturally occurring substance in the fetus’s body called prostaglandin. At birth, fetal production of prostaglandin decreases and the ductus arteriosus closes.

In some infants, this blood vessel does not close, which is a condition called a patent (open) ductus arteriosus. These infants are given a prostaglandin inhibitor, a medicine to stimulate the closure of this blood vessel.

When an infant has certain other congenital heart defects, a medicine (a form of prostaglandin) is often given by vein to keep the ductus arteriosus open. Keeping this blood vessel open allows the blood to continue circulating until surgery or another procedure can be done to correct the related defect and allow normal blood flow.


Many people with congenital heart defects need to take anticoagulants (blood-thinners). Common reasons for this type of treatment include heart valve replacements, heart rhythm disorders or prior complicated surgeries such as the Fontan operation. Blood-thinning medicines slow blood clotting, preventing complications like blood clots forming on artificial valves, valve obstruction and blood clots traveling to the brain and causing stroke.

Anticoagulants are usually given by mouth. In some cases they’re given by vein (intravenously) or by injecting them just under the skin (subcutaneously).

Bleeding may be a complication of taking these medications. Tell your doctor if you begin to bruise easily, or you notice unusual bleeding anywhere including gums or nosebleeds.

Oral Anticoagulants

These mainly include aspirin or clopidogrel (Plavix) and warfarin (Coumadin). These medications decrease the clotting tendency by interfering with platelets or blocking the body’s production of clotting substances. Your cardiologist will decide which one is right for you.

Aspirin tends to cause fewer bleeding complications than clopidogrel or warfarin, but it may not block clotting enough. It may also upset your stomach.

Clopidogrel doesn’t require regular blood test monitoring, but it affects platelet function and bleeding times for up to 7–10 days. You may need to avoid elective dental work and elective operations while taking aspirin or clopidogrel due to risks of bleeding.

Warfarin increases your risk of serious bleeding problems, even when the dose is at the recommended level. Carefully and regularly monitoring the level of blood thinning by testing is required while on warfarin.

If you take warfarin, you may need to limit some physical activities to reduce the chance of injury, particularly a head injury.

Using warfarin during pregnancy also can cause malformations in an unborn child, so discuss the risks of blood thinners with your doctor before you get pregnant.

Intravenous Anticoagulants

Intravenous heparin acts rapidly to thin the blood. When it’s stopped, the effect also wears off rapidly. Oral anticoagulants are longer-acting, so if you need elective surgery (including dental surgery), these medications may need to be stopped and intravenous or subcutaneous, shorter-acting heparin begun in the hospital before surgery often referred to as “bridging”. Your doctor will decide if bridging is necessary based on your heart condition.

Subcutaneous Anticoagulants

There are two blood-thinning medications: heparin and low-molecular-weight heparin (Lovenox). Both can be injected just underneath the skin (subcutaneously). This is sometimes done if it’s required for a longer time (e.g., during pregnancy) and eliminates the need for an intravenous line long-term. Your cardiologist will determine which type of blood-thinning medication is best for you.

Medication Monitoring

If you’re taking warfarin, your doctor will regularly monitor the blood-clotting level to be sure your dosage is correct. A value called the INR (international normalized ratio) tests how quickly your blood clots. Your warfarin dosage will be carefully adjusted to maintain an INR level appropriate for your heart condition. You must take your medicine exactly as prescribed. You also must have your blood tested regularly according to your doctor’s orders. If you need heparin or low-molecular-weight heparin, blood tests are also required to check that the dose is correct.

Medication and Diet Interactions with Warfarin

Many over-the-counter or prescription medicines can interact with warfarin and change your INR, which can be hazardous. These medicines include most antibiotics, several pain medicines (e.g., non-steroidal anti-inflammatory drugs) and medications for acid reflux such as cimetidine (Tagamet).

If you’re taking warfarin and start a new prescription or over-the-counter medication, check with your doctor. It’s important to determine if this might affect the INR and if you need more frequent blood testing.

In general, avoid aspirin when you’re being treated with warfarin. If you have a mechanical heart valve, low-dose aspirin may be added to warfarin to help prevent blood clots from forming. Discuss this with your cardiologist.

Certain foods also interfere with how your body processes warfarin. Your cardiologist will discuss foods to avoid or eat regularly while taking warfarin. If you’re on warfarin, always ask your doctor about your diet and before taking any other medicines, including vitamins and herbal preparations.

Anticoagulation in Pregnancy

Women who require anticoagulation and become pregnant need to take special precautions. Warfarin poses significant risk to the fetus, especially in the first trimester. Many women on warfarin are switched to heparin during the first weeks of pregnancy. Some may then stay on heparin throughout the pregnancy and delilvery. Others may be started back on warfarin during the middle of the pregnancy, then switched back to heparin for the delivery.

It’s critical to discuss management of anticoagulation during pregnancy with your cardiologist and obstetrician. The care must be tailored for each woman.




This post briefly touches on several categories of medications. Medications used to treat congenital heart defects are very strong and can be dangerous if they are not given correctly. It is important to know how to give medicine to your child safely. Please read all labels carefully. Please consult your child’s pediatric cardiologist for more information, including side effects.