Drugs used to Treat Patients with Congenital Heart Conditions

Not all patients with cardiac problems will require the use of medication. If the patient does need it, the drugs prescribed will depend on the nature of the heart condition, and the degree of symptoms they are showing. All of the drugs have a chemical or generic name which identifies the ‘ingredients' of the medication, but the pharmaceutical companies which make the drugs also give them a company or proprietary name, so there may be several names for the same drug.

Anti-arrhythmic Drugs

There are many anti-arrhythmic drugs such as Verapamil, Sotalol, Disopyramide, Lignocaine, Mexilitene, Flecainide, and Amiodarone. They are used to control arrhythmias - irregular or abnormal heartbeats.


These are used to treat infection as in patients without heart problems.


These drugs thin the blood and are used in patients who have an artificial heart valve, to prevent blood clots forming in the valve. Warfarin is the drug used and regular blood tests are essential to assess the amount of thinning and to adjust the dose, home testing kits are now suitable for many patients to use. All patients on this drug should carry a card with them detailing the dose and result of the latest blood test, so that they receive the correct treatment in an emergency.

Any medicines containing Aspirin should be avoided when taking Warfarin, as it is also an anticoagulant. Aspirin is sometimes used in children with heart conditions as it reduces the stickiness of the platelets in the blood. Heparin is used by intravenous infusion to keep the blood thin, for example during heart surgery or cardiac catheters. Sometimes drugs are used to dissolve blood clots, for example streptokinase or TPA. These clots may occur after surgery, catheters or at other times, especially if the blood is very thick (polycythaemic).


This increases the force of contraction of the heart muscle making it more efficient, and it also slows down the electrical impulses within the heart. It is used to give extra support to the heart muscle and to slow down the heart if it is beating too fast. It can occasionally make the patient sick or nauseated and they may lose their appetite.


Frusemide and Chlorothiazide

These drugs enable the kidneys to produce and excrete more urine. When the heart is not working very efficiently it causes the body to retain fluid within the lungs and the liver. Consequently the lungs become heavier and work less efficiently causing the patient to become breathless, which often results in difficulty in feeding in babies. These drugs tend to excrete potassium, sodium, and chloride in the urine and supplements of these substances are sometimes needed.

Spironolactone / Amiloride

These are slightly weaker diuretics that also do not cause the excretion of potassium. They are often used together with one of the other diuretics.


These are drugs given, usually on the intensive care unit to increase the efficiency of the heart. They are often used for a short time after heart operations. Examples are Dobutamine, Milrinone and Adrenaline.

Potassium supplements

These are given with the diuretics to help replace the lost potassium, but the patient will probably not like the taste very much.


Another drug that reduces the rate and force of contraction of the heart muscle. It is used to treat fast heart rates, high blood pressure, and to relieve the spasms of the heart muscle in Fallot's Tetralogy.

Pulmonary vasodilators

These are used to reduce the lung artery pressure, to treat pulmonary hypertension. They may be breathed in (e.g. nitric oxide) after heart surgery, they may be taken by intravenous infusion (e.g. Prostacyclin) or they may be taken by mouth (e.g. Bosentan or Sildenafil).


This can safely be given if the patient has a temperature. Use the recommended dose as shown according to the age of the patient.


Captopril, Enalapril and Lisinopril

These drugs are vasodilators, which means that they increase the size of the blood vessels and reduce blood pressure. They are also used to lower high blood pressure, but can also be used if the heart action is weak, as by reducing the blood pressure it reduces the work of the heart.

When a drug is prescribed it is always best to check with the doctor

All medicines should be measured accurately. All pharmacies now have syringes for measuring correct dosage, ask if you need one. If possible medication should be sugar free, if not follow the medicine with a drink of water to clean the syrup off the teeth. It is always inadvisable to put medicine in a baby's bottle as if they do not finish their bottle they will not have had the correct dose. Check with your doctor what to do should the patient vomit back their dose of medicine.

"In the beginning we wondered how we'd remember when all the different drugs had to be given and how we'd give them to such a small baby. But it wasn't long before we got in to a routine, just like you do with preparing feeds and changing nappies; using a syringe made it really easy. It was simple to measure the correct dose and the medicine could be given in smaller amounts right into the back of the mouth, so it was less likely to be spat out or spilt. We now use syringes for all our children!"