Antiarrhythmic Pregnancy: Animal studies showed no evidence of teratogenicity, but 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 or premature delivery, 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. Use in pregnancy only if the potential benefits outweigh the possible risk to the foetus; monitor the neonate very carefully for 48-72 hours after delivery if maternal therapy could not be interrupted 2-3 days before the birth date. Breast-feeding is not recommended (eMC §4.6).

Sotalol

Brand names: Beta-Cardone, Sotacor

Used in: Atrial Fibrillation

Sotalol is an antiarrhythmic with both non-selective beta-blocking and class III (potassium-channel-blocking) activity, used for atrial and 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: Initial dose 80 mg, administered either singly or as two divided doses. Most patients respond to a daily dose of 160 to 320 mg administered in two divided doses at approximately 12 hour intervals.

Route: Oral

Frequency: Initially 80 mg daily as a single dose or in two divided doses; maintenance in two divided doses at approximately 12-hour intervals. Adjust dosage gradually, allowing 2-3 days between dosing increments in order to attain steady state and to allow monitoring of QT 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 (eMC §4.2/§4.4).

Source: eMC SPC for Sotalol 40mg Tablets (§4.2 Posology). The dosage must be individualised and based on the patient's response. Initiation of treatment or any change 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. Proarrhythmic events can occur not only at initiation of therapy but also with each upward dosage adjustment; §4.4 states that initiating therapy at 80 mg with gradual upward titration thereafter reduces the risk of proarrhythmia, and that the incidence of torsades de pointes is dose dependent (severe proarrhythmia was 2% at doses up to 320 mg and more than doubled at higher doses). 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; where possible reduce the dosage gradually over one to two weeks. §4.4: use caution if the QTc exceeds 500 msec whilst on therapy, and give serious consideration to reducing the dose or discontinuing therapy when the QTc interval exceeds 550 msec; do not use in patients with hypokalaemia or hypomagnesaemia prior to correction of the imbalance. Hepatic impairment: sotalol is not subject to first-pass metabolism and patients with hepatic impairment show no alteration in clearance — no dosage adjustment is required. PAEDIATRIC: the UK SPC states 'There is no relevant use of Sotalol in the paediatric population', so no paediatric dose is given here; if paediatric use is contemplated, seek specialist advice and verify against a children's formulary. CAPTURE CAVEATS for the clinician verifier: (1) eMC §4.5 (interactions) was not included in the fetched bundle — the interactions listed below are drawn from eMC §4.4 and from the US label §7 as tagged, and must be verified against SPC §4.5; (2) the less-than / greater-than comparator symbols were stripped from the SPC text when it was captured, affecting the renal dosing table and the renal-failure contraindication — verify those numeric thresholds against the source SPC before use.

Dose adjustments

Renal

Sotalol is excreted mainly in urine, so the dosage should be reduced when the creatinine clearance is less than 60 ml/min. eMC §4.2 table (comparator symbols were stripped when the SPC text was captured — verify against the source SPC): creatinine clearance 60 ml/min — recommended dose; 30-60 ml/min — half the recommended dose; 10-30 ml/min — a quarter of the recommended dose; 10 ml/min — avoid sotalol. Creatinine clearance can be estimated from serum creatinine by the Cockroft and Gault formula: men (140 - age) x weight (kg) / 72 x serum creatinine (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).

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.

US labelling (FDA)

Reference — US labelling, may differ from UK

Sotalol hydrochloride tablets: Initial dosage in adults is 80 mg twice daily. Increase the dose as needed in increments of 80 mg/day, every 3 days to a maximum 320 mg total daily dose ( 2.2 ) Pediatrics: Dosage depends on age ( 2.4 ) 2.1 General Safety Measures for Initiation of Oral Sotalol Therapy Withdraw other antiarrhythmic therapy before starting sotalol hydrochloride tablets and monitor for a minimum of 2 to 3 plasma half-lives prior to initiating sotalol hydrochloride tablets therapy if the patient's clinical condition permits [see Drug Interactions ( 7 )] . Hospitalize patients being initiated or re-initiated on sotalol for at least 3 days or until steady-state drug levels are …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-04-03. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

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; hypotension (except due to arrhythmia)
Uncontrolled congestive heart failure; cardiogenic shock; 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 in the formulation
Metabolic acidosis
Renal failure — captured SPC text reads 'renal failure (creatinine clearance 10 ml/min)'; the comparator symbol was stripped in capture, so verify the threshold against the source SPC

Side effects

Proarrhythmia — the most significant adverse effect, including torsades de pointes and new sustained VT/VF (clinical trial rates: torsades de pointes 4.1% in sustained VT/VF, 1.0% in NSVT/PVC, 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
Other (common): rash, muscle spasms, sleep disorder, altered mood, depression, anxiety, sexual dysfunction, visual disturbances, hearing disturbances, pyrexia; frequency not known — alopecia, hyperhidrosis, thrombocytopenia

Interactions

(eMC §4.4) Concomitant use of sotalol with other medications associated with torsades de pointes — risk of torsades is also increased by prolongation of the QT interval, slow heart rate, reduction in serum potassium and magnesium, and high plasma sotalol concentrations
(US label §7.1) Class I or Class III antiarrhythmics and other QT-prolonging drugs — discontinue Class I or Class III agents for at least three half-lives before dosing with sotalol; disopyramide, quinidine, procainamide and amiodarone are not recommended as concomitant therapy
(US label §7.2) Digitalis glycosides, diltiazem, verapamil and beta-blockers — slow AV conduction and decrease heart rate; increased risk of bradycardia or hypotension
(US label §7.3) Catecholamine-depleting agents such as reserpine and guanethidine — excessive reduction of resting sympathetic tone; monitor for hypotension and marked bradycardia which may produce syncope
(US label §7.4/§7.7) Insulin and antidiabetic drugs may need dose adjustment; aluminium- or magnesium-based antacids reduce sotalol exposure

Clinical monograph

How it works

It blocks beta-adrenoceptors and prolongs cardiac repolarisation (class III), which is antiarrhythmic but also lengthens the QT interval.

Prescribing in practice

It prolongs the QT interval and can cause torsades de pointes — monitor the QT/ECG, correct electrolytes (potassium, magnesium), and avoid other QT-prolonging drugs.
It is renally cleared — reduce the dose in renal impairment.
Usual beta-blocker cautions apply (avoid in asthma; do not stop abruptly).

Monitoring

Monitor ECG (QT interval), heart rate, electrolytes and renal function; often initiated with ECG monitoring.

Counselling the patient

Report palpitations, fainting or dizziness.
Do not stop it suddenly.
Keep up your monitoring blood tests and ECGs.

Evidence & guidelines

Used for atrial and ventricular arrhythmias, with careful QT and electrolyte monitoring because of torsades risk.

Reference: NICE NG196 (AF); ESC 2020 AF Guidelines; SPC Sotacor; 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.

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