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Class III antiarrhythmic / Beta-blocker

Research-based

Betapace (Sotalol)

An antiarrhythmic medication used to control dangerous heart rhythm abnormalities (arrhythmias) in dogs with DCM, particularly ventricular premature complexes (VPCs).

Quick facts

Drug class

Class III antiarrhythmic / Beta-blocker

Estimated cost

$15–50/month. Generic sotalol is widely available and relatively affordable.

Also known as

Betapace, Sotylize (Sotalol)

How it works

Sotalol has two mechanisms: as a beta-blocker, it slows the heart rate and reduces the heart's demand for oxygen. As a Class III antiarrhythmic, it prolongs the time between heartbeats, helping to suppress dangerous arrhythmias like VPCs and ventricular tachycardia that can cause sudden death in Dobermans.

Common dosage

Typically 1.5–3.0 mg/kg twice daily. Dosage is carefully adjusted based on Holter monitor results. Your cardiologist will likely start at a lower dose and increase as needed while monitoring your dog's heart rhythm.

Dosages vary — your vet will determine the right dose for your dog.

Side effects to watch for

  • Slow heart rate (bradycardia)
  • Low blood pressure — watch for weakness or wobbliness
  • Lethargy or reduced energy
  • GI upset (vomiting, diarrhea)
  • Worsening of heart failure in some cases
  • Do not stop suddenly — must be tapered gradually

Drug interactions

  • Other beta-blockers — dangerous combination, risk of severe bradycardia
  • Calcium channel blockers — combined use can cause dangerously slow heart rate
  • Insulin — sotalol may mask signs of low blood sugar in diabetic dogs
  • Pimobendan — generally safe to combine, but requires monitoring

Frequently asked questions

Other DCM medications

Important:Never start, stop, or adjust your dog's medication without consulting your veterinarian. The dosages and protocols described here are general references — your vet will determine the right approach for your dog based on their individual condition, weight, and overall health.