Cardiac arrhythmia is the medical term for an irregular heartbeat. Irregular heartbeats can include premature beats, slowed heartbeat, rapid heartbeat, atria fibrillation and ventricular arrhythmia. Since cardiac arrhythmia can be life-threatening, it is important for the condition to be controlled. Several medicines for cardiac arrhythmias can prevent arrhythmia episodes from occurring.
Beta Blockers
Beta blockers block the effects of adrenaline on the heart, so heart rate and output are reduced. These drugs also block the electrical impulses that can cause cardiac arrhythmia. Beta blockers should be used with caution in people who take antidepressants, asthma medications, allergy shots, diabetic medications and other high blood pressure drugs. The Texas Heart Institute recommends that anyone taking beta blockers avoid caffeine, alcohol and cold and cough medicines that contain aluminum. Common beta blocker side effects include fatigue, cold hands, drowsiness, dry mouth, cold feet, weakness, dry eyes, dizziness and dry skin. Rarely, beta blockers can cause vomiting, constipation, skin rash, depression, impotence, abdominal cramps, diarrhea, back pain, sore throat, joint pain, memory loss, hallucinations and confusion. Metoprolol, labetalol and bisoprolol are examples of beta blocker drugs.
Calcium Channel Blockers
Calcium channel blockers prevent abnormally fast heart rate by blocking the effects of calcium on the heart and blood vessels. Calcium channel blockers need to be used with caution in people taking other medications, as they can enhance or interfere with the effects of other medications. Tell your doctor if you are taking diuretics, eye medications, corticosteroids, calcium or vitamin D supplements, antiarrhythmic drugs, beta blockers, digitalis or ACE inhibitors. Common side effects of calcium channel blockers include flushing, heartburn, edema (swelling) and fatigue. Less common side effects include trouble swallowing, upset stomach, dizziness, constipation, numbness and tingling, very fast heartbeat, wheezing, shortness of breath, coughing and very slow heartbeat. Amlodipine, diltiazem and felodipine are examples of calcium channel blockers.
Antiarrhythmic Drugs
Antiarrhythmic drugs block electrical impulses that cause cardiac arrhythmia. Class IA antiarrhythmic drugs are used to treat atrial fibrillation, ventricular tachyarrhythmia, supraventricular tachyarrhythmia and flutter. Drugs in this class include quinidine, disopyramide and procainamide. Class IB antiarrhythmic drugs are used to treat ventricular tachyarrhythmia. Drugs in this class include mexiletine, tocainide, lidocaine and phenytoin. Class IC antiarrhythmic drugs are used to treat ventricular tachyarrhythmia and supraventricular tachyarrhythmia that have become life-threatening. Class IC drugs include moricizine, flecainide and propafenone. Nausea, dizziness, headache and diarrhea are common side effects associated with Class I drugs. Class IC drugs have the potential to increase the risk of sudden death in people who have had heart attacks or prolonged ventricular arrhythmia.
Anticoagulants
Anticoagulants, also known as blood thinners, prevent blood clots from forming. Because atrial fibrillation increases the risk for blood clot formation, people with this type of cardiac arrhythmia may be given anticoagulants. Aspirin is an over the counter drug that has anticoagulant properties. This drug makes it harder for platelets to stick together and form clots. Warfarin reduces the blood's ability to form clots. The American Heart Association indicates that warfarin seem to be more effective in preventing strokes caused by blood clots. Because anticoagulants can cause easy bruising and abnormal bleeding, they must be used carefully. Blood tests are done on a regular basis to determine if a person's clotting time is dangerously impaired.
