Sotalol should be used only in certain patients. Before taking sotalol, discuss the risks and benefits of treatment with your doctor. Although sotalol is effective for treating certain types of fast/irregular heartbeats, it can rarely cause a new serious abnormal heart rhythm (QT prolongation in the EKG). This problem can lead to a new type of abnormal (possibly fatal) heartbeat (torsade de pointes). If this new serious heart rhythm occurs, it is usually when sotalol treatment is first started or when the dose is increased. To reduce the risk of this side effect, you should begin sotalol treatment in a hospital so your doctor can monitor your heart rhythm for several days and treat the problems if they occur. Patients usually start with a low dose of sotalol. Your doctor will then slowly increase your dose depending on how you respond to the medication and how well your kidneys work. If you respond well to this medication, during this time in the hospital your doctor can determine the right dose of sotalol for you. Some sotalol products are used to treat certain types of fast/irregular heartbeats (atrial fibrillation/flutter). These products come with additional written information from the manufacturer for patients with atrial fibrillation/flutter. If you have these conditions, read the provided information carefully. Do not switch brands of sotalol without checking with your doctor. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when you suddenly stop this drug. Some people who have suddenly stopped taking similar drugs have had chest pain, heart attack, and irregular heartbeat. If your doctor decides you should no longer use this drug, your doctor may direct you to gradually decrease your dose over 1 to 2 weeks. When gradually stopping this medication, it is recommended that you temporarily limit physical activity to decrease strain on the heart. Get medical help right away if you develop: chest pain/tightness/pressure, chest pain spreading to the jaw/neck/arm, unusual sweating, trouble breathing, fast/irregular heartbeat.

Tiredness, slow heartbeat, and dizziness may occur. Less common side effects include headache, diarrhea, and decreased sexual ability. If any of these effects last or get worse, tell your doctor or pharmacist promptly. To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain). Get medical help right away if you have any very serious side effects, including: severe dizziness, fainting, sudden change in heartbeat (unusually faster/slower/more irregular), chest/jaw/left arm pain. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

A product that may interact with this drug is: fingolimod. Many drugs besides sotalol may affect the heart rhythm (QT prolongation in the EKG), including amiodarone, disopyramide, dofetilide, pimozide, procainamide, quinidine, macrolide antibiotics (such as clarithromycin, erythromycin), among others. Some products have ingredients that could raise your heart rate. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen). This medication may interfere with certain medical/lab tests, possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.