Limitations and side effects of antiarrhythmic medications
When your doctor determines that you need antiarrhythmic medicine to treat your arrhythmia, certain factors may limit the choice of medicines. These include:
- A weakened heart. Medicines such as beta-blockers and calcium channel blockers can make heart failure (HF) worse in people with weak hearts, and these medicines need to be used carefully. Your doctor may need to see you frequently after starting these medicines. Similarly, disopyramide, sotalol, and procainamide can make heart function worse and cause HF.
- Other medical conditions.
- Lung disease: People with lung diseases may get worse when treated with beta-blocking medicines.
- Liver and kidney diseases: Most of the antiarrhythmic medicines are eliminated from the body by the liver or the kidneys. In people with liver and kidney diseases, these medicines can build up in the body and then cause multiple side effects. For example, ibutilide, bretylium, sotalol, flecainide, tocainide, disopyramide, and procainamide are all eliminated from the body by the kidneys. These drugs need to be used carefully in people with kidney diseases. People with liver disease should not receive amiodarone.
- The risk of side effects. Most of the antiarrhythmic medicines can cause a variety of side effects. Some side effects are more of a nuisance (such as rash, upset stomach, diarrhea) while others can be more worrisome (blood disorders, difficulty breathing, confusion). Most antiarrhythmics also can cause arrhythmias: this is known as a proarrhythmic effect. The arrhythmias that these medicines cause can be very troublesome, including a specific type of ventricular tachycardia known as Torsades de Pointes. This side effect likely accounts for an increased risk of death. Although sudden death from taking antiarrhythmics is rare, it is more common among people whose heart muscle has been damaged, such as from a serious heart attack or heart disease (like cardiomyopathy). There are certain antiarrhythmic medicines (disopyramide, flecainide, procainamide, propafenone, and quinidine) that should be avoided in people with damaged heart muscle or heart disease.
The table below lists the major side effects in more detail.
Major side effects of medicines commonly prescribed to treat arrhythmias Antiarrhythmic medicine
Major side effects
Amiodarone Low white blood cell count, pulmonary fibrosis, liver abnormalities, over- or underactive thyroid, bluish skin discoloration, nausea, constipation, slow heart rate, tremor, unstable gait, numbness and tingling in the hands and feet Beta-blockers Wheezing, heart failure, slow heart rate, depression, fatigue, nightmares, impotence, low blood pressure Calcium channel blockers Heart failure, slow heart rate, constipation, low blood pressure Disopyramide Dry mouth, blurred vision, constipation, difficulty with urination, worsened glaucoma, low blood pressure, heart failure, proarrhythmia This medicine should not be taken by people with coronary artery disease, cardiomyopathy, congestive heart failure, or people who have had a heart attack.
Flecainide Heart failure, blurry vision, headache, arrhythmia, tremor This medicine should not be taken by people with coronary artery disease, cardiomyopathy, congestive heart failure, or people who have had a heart attack.
Ibutilide Heart block, nausea, low blood pressure, Torsades de Pointes Lidocaine Dizziness, numbness and tingling of the face and limbs, confusion, seizures Mexiletine Nausea, vomiting, dizziness, shaking (tremor), confusion Procainamide Lupuslike syndrome (rash, arthritis), heart failure, nausea, vomiting, rash, fevers, confusion, low blood pressure, proarrhythmia This medicine should not be taken by people with coronary artery disease, cardiomyopathy, congestive heart failure, or people who have had a heart attack.
Propafenone Metallic taste to food, nausea, vomiting, heart failure, proarrhythmia This medicine should not be taken by people with coronary artery disease, cardiomyopathy, congestive heart failure, or people who have had a heart attack.
Quinidine Nausea, diarrhea, abdominal cramping, decreased hearing, blurred vision, confusion, rash, low blood count (anemia), low platelet count (thrombocytopenia), low blood pressure, episodic syncope, proarrhythmia This medicine should not be taken by people with coronary artery disease, cardiomyopathy, congestive heart failure, or people who have had a heart attack.
Sotalol Same as beta-blockers, with more tendency to produce arrhythmias The FDA recently issued warnings about the medicine amiodarone (Cordarone). People taking this medicine should be aware that it may cause serious side effects that can lead to death, including lung damage, liver damage, and more severe heartbeat problems. Amiodarone is typically used for people who have severe symptoms when other medicines have failed. The FDA recommends that you talk to your doctor if you have any side effects or any concerns about taking amiodarone.1
| Author: | Monica Rhodes | Last Updated: September 26, 2006 |
| Medical Review: | Caroline S. Rhoads, MD - Internal Medicine Laurence Epstein, MD - Cardiac Electrophysiologist | |
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