Class III antiarrhythmic + non-selective β-blocker Pregnancy: Animal studies have shown no evidence of teratogenicity or other harmful effects on the foetus. There are no adequate and well-controlled studies in pregnant women; sotalol crosses the placenta and is found in amniotic fluid. Beta-blockers reduce placental perfusion, which may result in intrauterine foetal death and immature and premature deliveries, and adverse effects (especially hypoglycaemia and bradycardia) may occur in the foetus and neonate, with an increased risk of cardiac and pulmonary complications in the neonate postnatally. Sotalol should therefore be used in pregnancy only if the potential benefits outweigh the possible risk to the foetus. The neonate should be monitored very carefully for 48-72 hours after delivery if it was not possible to interrupt maternal therapy 2-3 days before the birth date. Breast-feeding: most beta-blockers, particularly lipophilic compounds, pass into breast milk to a variable extent, and breast-feeding is not recommended during administration.

Sotalol hydrochloride

Brand names: Beta-Cardone, Sotacor

Sotalol hydrochloride is a non-selective beta-blocker with additional class III antiarrhythmic action, used principally to maintain sinus rhythm in atrial and life-threatening ventricular arrhythmias.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: The initial dose is 80 mg, administered either singly or as two divided doses. The oral dosage should be adjusted gradually, allowing 2-3 days between dosing increments in order to attain steady state and to allow monitoring of QT intervals. Most patients respond to a daily dose of 160 to 320 mg administered in two divided doses at approximately 12 hour intervals.

Route: Oral (tablets)

Frequency: Initially once daily or in two divided doses; maintenance in two divided doses at approximately 12 hour intervals

Max: Some patients with life-threatening refractory ventricular arrhythmias may require doses as high as 480-640 mg/day. These doses should be used under specialist supervision and should only be prescribed when the potential benefit outweighs the increased risk of adverse events, particularly proarrhythmias.

Source: eMC SPC for Sotalol 40mg Tablets. Initiation: the initiation of treatment or changes in dosage should follow an appropriate medical evaluation including ECG control with measurement of the corrected QT interval and assessment of renal function, electrolyte balance and concomitant medications; as with other antiarrhythmic agents, sotalol should be initiated and doses increased in a facility capable of monitoring and assessing cardiac rhythm. The dosage must be individualised and based on the patient's response. Proarrhythmic events can occur not only at initiation of therapy but also with each upward dosage adjustment; initiating therapy at 80 mg with gradual upward titration thereafter reduces the risk of proarrhythmia. Torsade de pointes usually occurs within 7 days of initiating therapy or escalating the dose and its incidence is dose dependent — in clinical trials of patients with sustained VT/VF the incidence of severe proarrhythmia was 2% at doses up to 320 mg and more than doubled at higher doses. In patients already receiving sotalol, caution should be used if the QTc exceeds 500 msec on therapy, and serious consideration should be given to reducing the dose or discontinuing therapy when the QTc interval exceeds 550 msec. Sotalol should not be used in patients with hypokalaemia or hypomagnesaemia prior to correction of the imbalance. Withdrawal: in view of its beta-adrenergic blocking properties, treatment should not be discontinued suddenly, especially in patients with ischaemic heart disease (angina pectoris, prior acute myocardial infarction) or hypertension; if possible the dosage should be gradually reduced over a period of one to two weeks. Hepatic impairment: since sotalol is not subject to first-pass metabolism, patients with hepatic impairment show no alteration in clearance and no dosage adjustment is required. Paediatric: SPC 4.2 states 'There is no relevant use of Sotalol in the paediatric population' — no UK paediatric regimen is given. (The US label fetched via openFDA does contain a paediatric weight-based regimen; it is not reproduced here because it is not part of the UK SPC — verify against a children's formulary and specialist paediatric cardiology advice if paediatric use is contemplated.)

Dose adjustments

Renal

Because sotalol is excreted mainly in urine, the dosage should be reduced when the creatinine clearance is less than 60 ml/min. SPC 4.2 table (as fetched): creatinine clearance >60 ml/min — recommended dose; 30-60 ml/min — half the recommended dose; 10-30 ml/min — one quarter of the recommended dose; <10 ml/min — avoid sotalol (renal failure with creatinine clearance below 10 ml/min is also a contraindication, SPC 4.3). CAUTION FOR THE VERIFYING CLINICIAN: the greater-than and less-than symbols were stripped from the fetched SPC text, so the boundary bands of this table have been reconstructed from the row order and from the 4.3 contraindication — confirm the exact thresholds against the SPC before publication. The SPC states creatinine clearance can be estimated from serum creatinine by the Cockcroft and Gault formula: men (140 - age) x weight (kg) / (72 x serum creatinine in mg/dl); women the same x 0.85; when serum creatinine is given in micromol/l, divide the value by 88.4 (1 mg/dl = 88.4 micromol/l). Hepatic impairment: no dosage adjustment is required.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Sick sinus syndrome
Second and third degree AV heart block unless a functioning pacemaker is present
Congenital or acquired long QT syndromes; torsades de pointes
Symptomatic sinus bradycardia
Uncontrolled congestive heart failure; cardiogenic shock; hypotension (except due to arrhythmia)
Anaesthesia that produces myocardial depression
Untreated phaeochromocytoma
Raynaud's phenomenon and severe peripheral circulatory disturbances
History of chronic obstructive airway disease or bronchial asthma
Hypersensitivity to sotalol, other beta-blockers or any of the excipients
Metabolic acidosis
Renal failure (creatinine clearance below 10 ml/min)

Side effects

Proarrhythmia is the most significant adverse effect — torsade de pointes and other serious new ventricular arrhythmias; in clinical trials rates of torsade de pointes were 4.1% in patients with sustained VT/VF, 1.0% in NSVT/PVC and 1.4% in supraventricular arrhythmia
Cardiac (common): bradycardia, dyspnoea, chest pain, palpitations, oedema, ECG abnormalities, hypotension, arrhythmia, syncope, cardiac failure, presyncope
Nervous system (common): fatigue, dizziness, asthenia, light-headedness, headache, paraesthesia, dysgeusia
Gastrointestinal (common): nausea, vomiting, diarrhoea, dyspepsia, abdominal pain, flatulence
Psychiatric (common): sleep disorder, altered mood, depression, anxiety; also sexual dysfunction, visual disturbances, hearing disturbances, muscle spasms, rash and pyrexia
Discontinuation because of unacceptable adverse events was necessary in 18% of all patients in cardiac arrhythmia trials — most commonly fatigue 4%, bradycardia (below 50 bpm) 3%, dyspnoea 3%, proarrhythmia 2%, asthenia 2% and dizziness 2%. Cold and cyanotic extremities, Raynaud's phenomenon, increase in existing intermittent claudication and dry eyes have been seen with other beta-blockers.

Interactions

Other medications associated with torsades de pointes — concomitant use with sotalol increases the risk of torsades de pointes (SPC 4.4, cross-referring to 4.5)
Drugs or conditions reducing serum potassium and magnesium — hypokalaemia and hypomagnesaemia must be corrected before sotalol is used, as they increase the risk of torsades de pointes (SPC 4.4)
Section 4.5 (interactions) was not captured in the fetched eMC bundle — check the full interaction list against the SPC before publication
Cross-check (US label, not eMC): discontinue Class I or Class III antiarrhythmics for at least three half-lives before dosing with sotalol and avoid concomitant use of other QT-prolonging drugs; digitalis glycosides, diltiazem, verapamil and other beta-blockers increase the risk of bradycardia and hypotension; catecholamine-depleting agents such as reserpine and guanethidine may produce excessive reduction of resting sympathetic tone; insulin and antidiabetic drug doses may need adjustment; aluminium- or magnesium-based antacids reduce sotalol exposure

Clinical monograph

How it works

It combines non-selective beta-adrenoceptor blockade with potassium-channel blockade that prolongs cardiac repolarisation and the action potential, increasing the refractory period.

Prescribing in practice

Sotalol prolongs the QT interval and can provoke torsades de pointes, so correct hypokalaemia and hypomagnesaemia, avoid other QT-prolonging drugs, and follow recommended ECG-guided initiation as in the SPC.
It is renally cleared and accumulates in renal impairment, requiring dose reduction and greater caution.
Standard beta-blocker contraindications apply, including asthma, uncontrolled heart failure, marked bradycardia and high-grade heart block.

Monitoring

Monitor the ECG (especially QT interval and heart rate), serum electrolytes and renal function at initiation, after dose changes and during maintenance.

Counselling the patient

Do not stop the drug abruptly, as this can worsen arrhythmias.
Report palpitations, fainting or dizziness urgently.
Attend for the ECG and blood tests needed to use this medicine safely.

Evidence & guidelines

Sotalol's QT-prolonging, pro-arrhythmic profile is well established, and guidance such as that from NICE and the MHRA stresses ECG and electrolyte monitoring during use.

Reference: NICE NG196; ESC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways