# Sotalol: veterinary dose and monograph

> Sotalol is a veterinary cardiovascular drug. Antiarrhythmic with dual action — it is both a non-selective beta-blocker (class II) and a class III agent that prolongs repolarisation by blocking potassium channels. Indications include ventricular tachyarrhythmias / frequent ventricular premature complexes; boxer ARVC and other cardiomyopathy-associated ventricular ectopy; selected supraventricular tachyarrhythmias. This monograph lists 4 reference doses for dogs, cats, horses and rabbits, each with route, frequency and source.

Source: https://vetmasterji.com/drugs/sotalol · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Cardiovascular
- **Also known as:** Sotalol hydrochloride, Sotagard, Betapace
- **Species with doses:** Dogs, Cats, Horses and Rabbits
- **General dose range:** 1–2 mg/kg PO q12h — check the species tables for the indication
- **Routes:** PO
- **Last reviewed:** 1 October 2026

## Indications

- Ventricular tachyarrhythmias / frequent ventricular premature complexes
- Boxer ARVC and other cardiomyopathy-associated ventricular ectopy
- Selected supraventricular tachyarrhythmias
- Rate/rhythm control where combined beta- and class-III action is desired

## Sotalol dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Dogs

*Sotalol doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Ventricular tachyarrhythmia / ARVC | 1–3 mg/kg | PO | q12h | — |

- Ventricular tachyarrhythmia / ARVC: Papich 5e: 2 mg/kg q12h PO (medium/large dogs start 40 mg per dog q12h, increasing to 80 mg). Plumb’s p.1070: 1–2 mg/kg q12h (Fox; Moise; Atkins); 1–3 mg/kg twice daily (Henik); Boxers 1.5–3 mg/kg twice daily with mexiletine, or 40–80 mg per dog q12h. Titrate by Holter/ECG; do not stop abruptly.

### Cats

*Sotalol doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Ventricular/supraventricular arrhythmia | 1–2 mg/kg | PO | q12h | — |

- Ventricular/supraventricular arrhythmia: Papich 5e: 1–2 mg/kg q12h PO (10–20 mg per cat q12h). Plumb’s p.1070: 2 mg/kg PO twice daily (Atkins; Cote) — about ⅛ of an 80 mg tablet. Monitor for bradycardia and CHF.

### Horses

*Sotalol doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Atrial fibrillation / ventricular tachycardia | 1–3 mg/kg | PO | q12h | — |

- Atrial fibrillation / ventricular tachycardia: Papich 5e: atrial fibrillation 2 mg/kg PO q12h for 3 days; ventricular tachycardia 1 mg/kg PO q12h, increasing to 2–3 mg/kg q12h as needed.

### Rabbits

*Sotalol doses for rabbits*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Atrial / ventricular arrhythmia | 1.7 mg/kg | PO | q12h | — |

- Atrial / ventricular arrhythmia: Carpenter's 6th ed (Rabbit cardiovascular table): 1.7 mg/kg PO q12h for both atrial and ventricular arrhythmias.

## Contraindications

Significant bradyarrhythmia / high-grade AV block (without pacing), decompensated congestive heart failure, severe hypotension, bronchospastic disease (non-selective beta-blockade), and pre-existing marked QT prolongation. Hypokalaemia/hypomagnesaemia (proarrhythmia). Use caution with other QT-prolonging or negative-inotropic drugs. Known hypersensitivity.

## Species-specific warnings

> **Caution:** Cats: Monitor closely for bradycardia, hypotension and precipitation of CHF; dose conservatively (often per-cat) with ECG guidance.

## Adverse effects

- Negative inotropy — can worsen/precipitate heart failure
- Bradycardia, hypotension, lethargy/weakness
- Proarrhythmia (QT prolongation, torsades-type rhythms) — especially with electrolyte derangement
- GI upset
- Bronchoconstriction (non-selective beta-blockade)

## Drug interactions

- Other QT-prolonging drugs (some antiarrhythmics, macrolides, fluoroquinolones): additive torsades risk
- Other negative chronotropes/inotropes (diltiazem, digoxin, beta-blockers): additive bradycardia/AV block/myocardial depression
- Drugs causing hypokalaemia (loop/thiazide diuretics): increased proarrhythmia — keep potassium/magnesium normal
- Antacids: reduce absorption (separate dosing)

## Pregnancy and lactation

Limited veterinary data; beta-blockers can cause fetal bradycardia/growth effects — use only if the arrhythmia risk to the dam outweighs this.

## Monitoring

- ECG / Holter for efficacy AND QT interval (proarrhythmia)
- Heart rate, rhythm and blood pressure
- Serum potassium and magnesium (keep normal)
- Signs of worsening CHF (resting respiratory rate, effort)
- Never discontinue abruptly — taper to avoid rebound arrhythmia

## Toxicity and overdose

Overdose: profound bradycardia, hypotension, AV block, heart failure, bronchospasm and, paradoxically, life-threatening ventricular proarrhythmia (torsades de pointes) from excessive QT prolongation — markedly worsened by hypokalaemia/hypomagnesaemia.

Management: No single antidote. For bradycardia/hypotension: atropine, IV fluids, and beta-agonist support (high-dose); glucagon is useful for beta-blocker overdose. Correct potassium/magnesium and treat torsades with IV magnesium sulphate ± overdrive pacing/isoproterenol. Continuous ECG; supportive intensive care.

## Clinical pearls

- The dual beta-blocker + class-III action makes it a go-to for canine ventricular arrhythmias and Boxer ARVC
- Always normalise potassium and magnesium before/while dosing — hypokalaemia turns sotalol proarrhythmic
- Titrate with ECG/Holter; watch the QT interval, not just ectopy suppression
- Negative inotrope — use carefully in (or avoid in) decompensated heart failure
- Taper rather than stop suddenly to prevent rebound tachyarrhythmia

## Mechanism of action

Two antiarrhythmic mechanisms in one molecule: (1) non-selective beta-adrenergic blockade (class II) slows sinus rate, AV conduction and sympathetic-driven arrhythmias; (2) class III action blocks the delayed-rectifier potassium current (IKr), prolonging action-potential duration and the effective refractory period, which suppresses re-entrant ventricular arrhythmias. The same QT prolongation underlies its proarrhythmic potential.

## Formulations and products

- 40 mg tablet
- 80 mg tablet
- 160 mg tablet
- Sotagard — 40 / 80 mg tablet, Tablet (human-label)
- Sotalol — 40 / 80 mg tablet, Tablet (human-label)

## Storage

Tablets: 15–30 °C, dry, protected from light.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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## Frequently asked questions

### What is the dose of Sotalol for dogs?

Reference doses for Sotalol in dogs: 1–3 mg/kg PO q12h (Ventricular tachyarrhythmia / ARVC). Confirm against the label and the patient before use.

### What is the dose of Sotalol for cats?

Reference doses for Sotalol in cats: 1–2 mg/kg PO q12h (Ventricular/supraventricular arrhythmia). Confirm against the label and the patient before use.

### What is the dose of Sotalol for horses?

Reference doses for Sotalol in horses: 1–3 mg/kg PO q12h (Atrial fibrillation / ventricular tachycardia). Confirm against the label and the patient before use.

### When should Sotalol not be used?

Significant bradyarrhythmia / high-grade AV block (without pacing), decompensated congestive heart failure, severe hypotension, bronchospastic disease (non-selective beta-blockade), and pre-existing marked QT prolongation. Hypokalaemia/hypomagnesaemia (proarrhythmia). Use caution with other QT-prolonging or negative-inotropic drugs. Known hypersensitivity.

### What are the side effects of Sotalol in animals?

Negative inotropy — can worsen/precipitate heart failure; Bradycardia, hypotension, lethargy/weakness; Proarrhythmia (QT prolongation, torsades-type rhythms) — especially with electrolyte derangement; GI upset; Bronchoconstriction (non-selective beta-blockade).

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition
- Carpenter, Exotic Animal Formulary

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.