Sotalol Tablets

Important: Sotalol is a specialist antiarrhythmic medicine that requires careful clinical monitoring. Initiation of sotalol therapy must be carried out in a hospital setting under specialist cardiac supervision with continuous ECG monitoring. Online prescribing of sotalol for new patients or those in whom the dose has not yet been established is not appropriate through this service. This service is only able to support repeat prescriptions for patients who are already established and stable on sotalol, under the ongoing supervision of a cardiologist or specialist. The prescriber will assess whether repeat prescribing through this service is clinically appropriate for your individual circumstances.

Living with a heart rhythm condition can affect your daily life, and finding the right medicine to manage arrhythmia is an important part of your cardiac care. Sotalol tablets are a prescription-only medicine used in adults for the treatment and prevention of certain cardiac arrhythmias. Sotalol belongs to the class III antiarrhythmic and beta blocker categories of medicines, giving it a dual action on heart rhythm management. Because sotalol requires careful initiation under specialist cardiac supervision, this service is only appropriate for patients already established on the medicine.

Sotalol tablets are an oral prescription medicine containing sotalol hydrochloride as the active ingredient. Sotalol has a dual mechanism of action: it is both a non-selective beta adrenoceptor blocker and a class III antiarrhythmic agent. This combination of properties distinguishes sotalol from standard beta blockers used for hypertension and makes it particularly suited to cardiac rhythm management.

Sotalol is licensed in the UK for the following indications: treatment of symptomatic sustained ventricular tachycardia; prevention of paroxysmal atrial fibrillation and atrial flutter; prevention of paroxysmal supraventricular tachycardias including nodal tachycardias, AV tachycardias associated with Wolff-Parkinson-White syndrome, and atrial tachycardias; and maintenance of sinus rhythm following electrical cardioversion.

Sotalol is not licensed for the treatment of hypertension. Its use is limited to arrhythmia treatment and prevention as described above.

Sotalol has a narrow therapeutic index, meaning the difference between an effective dose and a potentially harmful dose is relatively small. This is why initiation of treatment and any dose changes must be carried out under specialist supervision with ECG monitoring, and why ongoing cardiac monitoring is an essential part of safe treatment.

Sotalol lowers blood pressure through two distinct mechanisms that together control both the rate and the electrical behaviour of the heart.

Beta Adrenoceptor Blockade

Sotalol blocks beta-1 and beta-2 adrenoceptors in the heart. This reduces the heart rate and slows conduction through the atrioventricular node, the electrical bridge between the upper and lower chambers of the heart. Reducing the rate of electrical conduction helps to control arrhythmias that involve rapid or abnormal impulses travelling through the heart.

Class III Antiarrhythmic Action

Sotalol also prolongs the cardiac action potential duration and the effective refractory period. The action potential is the electrical signal that triggers each heartbeat. By lengthening the time between signals, sotalol makes the heart less susceptible to the initiation of rapid abnormal rhythms. This class III antiarrhythmic action distinguishes sotalol from standard beta blockers and is the basis for its use in ventricular tachycardia and the prevention of supraventricular arrhythmias.

The combination of rate slowing through beta blockade and action potential prolongation through class III activity gives sotalol its dual antiarrhythmic profile. However, action potential prolongation also carries the risk of triggering a specific type of dangerous arrhythmia called torsades de pointes, particularly at higher doses or in the presence of low potassium or magnesium levels. This proarrhythmic risk is the primary reason sotalol requires specialist initiation and ongoing monitoring as part of cardiovascular therapy.

Always take sotalol exactly as your prescriber instructs. The information below summarises key points from the current UK SmPC. Read the Patient Information Leaflet supplied with your medicine before starting treatment.

• Take sotalol twice daily, at approximately the same times each morning and evening, approximately 12 hours apart.
• Sotalol should be taken on an empty stomach, at least two hours before or after a meal. Food reduces the absorption of sotalol.
• Swallow the tablet whole with a glass of water.
• If you miss a dose, take it as soon as you remember. If it is close to the time of your next scheduled dose, skip the missed dose and continue as normal. Do not take two doses at once.
• Do not stop taking sotalol suddenly without speaking to your specialist or prescriber first. Stopping sotalol abruptly can trigger a rebound in heart rate and potentially precipitate arrhythmias. Your specialist will advise on how to reduce the dose gradually if stopping is necessary.
• Regular monitoring is an important part of taking sotalol safely. Your specialist will arrange ECG recordings, kidney function tests, and electrolyte checks (particularly potassium and magnesium) at intervals. Low potassium or magnesium increases the risk of torsades de pointes.
• Always report any new palpitations, dizziness, fainting, or changes in your heart rhythm to your cardiac care team promptly.

Sotalol tablets are available in three strengths. All dose decisions, including the starting dose, dose titration, and any dose adjustments, must be made by a specialist with access to cardiac monitoring. Do not change your dose without first consulting your specialist.

Sotalol 40 mg Tablets

The 40 mg tablet supports lower doses and fine dose titration. It may be used during the careful dose increase process under specialist supervision, or as a maintenance dose in patients stabilised at a lower total daily dose.

Sotalol 80 mg Tablets

The 80 mg tablet is commonly used as part of the standard therapeutic dose range. The total daily dose is divided into two equal doses taken approximately 12 hours apart. Many patients are maintained on a total daily dose of 160 mg (two 80 mg doses) or 240 mg (two 120 mg doses, achievable using the 80 mg and 40 mg tablets together). The appropriate dose for arrhythmia control is determined by clinical response and cardiac monitoring findings.

Sotalol 160 mg Tablets

The 160 mg tablet allows larger twice daily doses for patients who require more intensive antiarrhythmic therapy under specialist direction. Higher doses carry a greater risk of proarrhythmic effects, including torsades de pointes, and are only used under close specialist supervision. The maximum recommended daily dose is 640 mg, but most patients will be maintained at significantly lower doses. All dose escalation must be conducted in a hospital or monitored specialist setting.

Sotalol can cause serious side effects in addition to the more common class effects seen with beta blockers. The information below is based on the current UK SmPC. Refer to the Patient Information Leaflet for the full list.

Common Side Effects (may affect up to 1 in 10 people)

• Fatigue or tiredness.
• Dizziness or lightheadedness.
• Slow heart rate (bradycardia).
• Breathlessness on exertion.
• Cold or numb hands and feet.
• Headache.

Uncommon Side Effects (may affect up to 1 in 100 people)

• Low blood pressure (hypotension).
• Sleep disturbances or vivid dreams.
• Nausea or gastrointestinal discomfort.
• Worsening heart failure in susceptible patients.

Serious Side Effects Including Proarrhythmia

Sotalol can cause new or worsening arrhythmias, including potentially fatal arrhythmias. This is a known proarrhythmic risk and is the reason sotalol requires specialist initiation and monitoring.

• Torsades de pointes: this is a specific type of ventricular tachycardia associated with QT interval prolongation. It can be triggered by sotalol, particularly at higher doses, with low potassium or magnesium levels, or in certain patient groups. It may feel like rapid palpitations, severe dizziness, or fainting. It can be life threatening. If you experience these symptoms, seek emergency medical help immediately by calling 999.
• QT interval prolongation on ECG, which increases the risk of torsades de pointes.
• Bronchospasm in patients with airways disease.
• Worsening arrhythmia or new arrhythmia during treatment.

Report any new symptoms including palpitations, dizziness, fainting, or breathlessness to your cardiac care team promptly. Do not wait for a routine appointment. In an emergency, call 999.

Report any suspected side effect to your prescriber, pharmacist, or via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Sotalol Tablets May Be Suitable If You:

• Are an adult with a confirmed diagnosis of one of the licensed arrhythmia indications listed in the SmPC.
• Have been initiated on sotalol in a hospital setting under specialist cardiac supervision with continuous ECG monitoring.
• Are established and stable on sotalol and require a repeat prescription under ongoing specialist supervision.

Sotalol Tablets Are Not Suitable If You:

• Have asthma or significant obstructive airways disease. Sotalol is a non-selective beta blocker and is contraindicated in these conditions.
• Have significant sinus bradycardia (a very slow resting heart rate below 50 beats per minute before treatment).
• Have second or third degree heart block or sick sinus syndrome.
• Have congenital or acquired long QT syndrome. Sotalol prolongs the QT interval and is contraindicated in patients who already have a prolonged QT interval.
• Have uncompensated heart failure.
• Have cardiogenic shock.
• Have low potassium or low magnesium levels that have not been corrected. These electrolyte abnormalities significantly increase the risk of sotalol-induced torsades de pointes.
• Have severe kidney impairment. Sotalol is almost entirely eliminated by the kidneys, and dose adjustment or avoidance is required in renal impairment.
• Are taking other medicines that prolong the QT interval. The concurrent use of QT-prolonging medicines with sotalol significantly increases the risk of serious arrhythmias. Your specialist will review all your medicines carefully.
• Are under 18 years of age.
• Have a known allergy or hypersensitivity to sotalol or any excipient listed in the SmPC.

Sotalol has clinically significant interactions with a number of medicines. The following are of particular importance:

• Medicines that prolong the QT interval: combining sotalol with other QT-prolonging medicines substantially increases the risk of torsades de pointes. This includes certain antiarrhythmics, some antibiotics (such as moxifloxacin), some antipsychotics, and several other classes. Your specialist must review all your medicines before and during sotalol treatment.
• Medicines that lower potassium or magnesium, including some diuretics, corticosteroids, and laxatives: these increase the risk of torsades de pointes by reducing the electrolyte levels that protect against this arrhythmia.
• Antidiabetic medicines including insulin: sotalol may mask some hypoglycaemia warning signs. Patients with diabetes must monitor blood glucose carefully.
• Calcium channel blockers of the verapamil or diltiazem type: combined use with sotalol can cause excessive slowing of the heart and impaired cardiac conduction.
• Antacids: aluminium and magnesium hydroxide containing antacids can reduce sotalol absorption. Take sotalol at least two hours before or after antacids.

Your specialist and prescriber must review all current medicines before and during sotalol treatment. This is an essential part of safe cardiovascular therapy.

Sotalol is a Prescription Only Medicine that requires specialist cardiac supervision. Initiation of sotalol is not appropriate through an online prescribing service. This service is only able to support repeat prescriptions for patients who are already established and stable on sotalol under ongoing specialist oversight.

During your online consultation with Pharmacy Planet, a registered prescriber will review the information you provide, including confirmation that you are already established on sotalol under specialist supervision, your current dose, any recent ECG findings or monitoring results, and your current medicines. The prescriber will determine whether a repeat prescription through this service is clinically appropriate for your individual situation.

Please ensure your cardiologist or arrhythmia specialist remains your primary point of contact for the management of your heart rhythm condition. Keep them informed of all medicines you are prescribed through any service. Your cardiac care team is best placed to monitor your ECG, adjust your dose, and respond to any changes in your heart rhythm.

Store below 25°C. Store in the original packaging to protect from moisture and light. Keep out of the sight and reach of children. Do not use after the expiry date printed on the packaging. Do not dispose of medicines via household waste or wastewater. Return unused or out of date tablets to your pharmacist for safe disposal. Full storage instructions are provided in the Patient Information Leaflet supplied with your medicine.

Pharmacy Planet is a GPhC-registered online pharmacy providing access to prescription medicines through a clinically led consultation process. Our registered prescribers and pharmacists are committed to patient safety, clinical accuracy, and responsible prescribing. We follow GPhC standards, MHRA guidance, and ASA advertising regulations in all aspects of our service. For specialist medicines such as sotalol, our prescribers exercise particular care to ensure that repeat prescribing is only supported where appropriate specialist oversight is already in place. Every prescription is reviewed and dispensed by qualified healthcare professionals. If you have questions about sotalol, heart rhythm management, or any other aspect of your cardiovascular therapy, our pharmacy team is available to help. We are committed to transparent, patient centred care that complements, not replaces, your cardiac specialist team.

References

1. Electronic Medicines Compendium (eMC). Sotalol hydrochloride 40 mg, 80 mg and 160 mg tablets — Summary of Product Characteristics. https://www.medicines.org.uk/emc. Accessed May 2026.
2. Joint Formulary Committee. British National Formulary (BNF). Sotalol hydrochloride. BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk. Accessed May 2026.
3. NHS. Sotalol. https://www.nhs.uk/medicines/sotalol. Accessed May 2026.
4. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card — report a side effect. https://yellowcard.mhra.gov.uk. Accessed May 2026.

Beta Blocker Tablets

The table below compares beta blocker tablets available at Pharmacy Planet. Beta blockers reduce heart rate and cardiac output to lower blood pressure. They differ in cardioselectivity, additional properties, and licensed indications.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.