AFib Drug Side Effects

AFib Drug Side Effects

Know the Side Effects of Atrial Fibrillation Medications

The medications used to treat atrial fibrillation vary from patient to patient depending on several factors. A similar statement can be made about the side effects of these drugs, so it is important to recognize the potential challenges you may face if you take these prescriptions.

Angiotensin-Converting Enzyme (ACE) Inhibitors

The ACE inhibitors, which include benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec) and ramipril (Altace) among others, have similar adverse effects. The most common are cough, drowsiness, elevated potassium levels, headache, low blood pressure, rash, unusual taste in the mouth and weakness.


The most likely reactions to anti-arrhythmics are dizziness, fatigue and nausea. Otherwise, here are some specific adverse effects associated with individual drugs.

  • Amiodarone (Cordarone, Pacerone). Hypothyroidism, hyperthyroidism, skin hypersensitivity to sunlight, pulmonary fibrosis (relatively rare and life-threatening)
  • Dofetilide (Tikosyn). Headache, fainting, ventricular arrhythmia (rare)
  • Dronedarone (Multaq). Diarrhea, indigestion, nausea, stomach pain, vomiting, redness, rash, itching, slowed heartbeat, lung inflammation, low magnesium and potassium levels
  • Flecainide (Tambocor). Blurry vision, breathing difficulties, tight chest, fainting, increased risk of death in people with a history of heart attack or cardiomyopathy, mental fogginess, racing pulse or heartbeat, tingling around the mouth, tremors
  • Propafenone (Rythmol). Anxiety, constipation, headache, increased risk of death in people with a history of heart attack or cardiomyopathy, mental fogginess, salty or metallic taste in the mouth, tremors, tingling around the mouth
  • Sotalol (Betapace). Blurry vision, chest pain, confusion, diarrhea, fast, slow or irregular heartbeat or pulse, shortness of breath, sweating, swelling of the face, fingers, feet or lower legs, tight chest, ventricular arrhythmia (rare), wheezing

Beta Blockers

Typical adverse reactions to beta blockers may include blurry vision, cold hands and feet, diarrhea, fatigue, low blood pressure, muscle and stomach cramps, nausea, nightmares, rash and vomiting. Here is a spotlight on specific drugs.

  • Acebutolol (Sectral). Dizziness, slow heartbeat, trouble sleeping
  • Atenolol (Tenormin). Breathing problems, confusion, sweating, tight chest, wheezing
  • Carvedilol (Coreg). Allergy, chest pain or tightness, swelling of the ankles, feet or lower legs, pain, slow heartbeat, weight gain
  • Metoprolol (Lopressor). Chest pain or discomfort, confusion, shortness of breath, slow heartbeat, sweating, unusual weakness
  • Nadolol (Corgard). Constipation, depression, impotence, insomnia, low blood pressure, shortness of breath, slow heart rate, sore throat, wheezing
  • Propranolol (Inderal). Dizziness, insomnia, vision changes

Calcium Channel Blockers

Among the more common drugs in this category are amlodipine (Norvasc), diltiazem (Cardizem), nifedipine (Adalat), nicardipine (Cardene) and verapamil (Calan). The side effects are similar, with the most common one being dizziness. Others include constipation, headache, fatigue, nausea, rapid heartbeat, rash and swelling of the lower legs and feet.


Patients taking dabigatran (Pradaxa) may experience acid stomach, belching, black stools, burning throat, constipation, diarrhea, heartburn, indigestion, nausea, stomach pain and vomiting.


The most common side effects of digoxin (Lanoxin) include dizziness, headache, mental changes, nausea, rash and vomiting. Less frequently patients experience rapid or slowed heartbeat.


If you take rivaroxaban (Xarelto) you may experience back pain, black or red stools, bleeding gums, bloody stools, breathing difficulties, unusual skin sensations (e.g., crawling, burning), coughing up blood, dizziness, headache, nosebleeds, numbness, paralysis, prolonged bleeding from cuts, red or dark urine and weakness in the legs.


The most serious potential side effect of warfarin (Coumadin) is bleeding. Therefore, routine blood testing is necessary. Common adverse effects include abdominal pain, loss of appetite and nausea.

These lists are not exhaustive. Regardless of which atrial fibrillation treatment you use, you should report any unusual event to your healthcare provider.