Class III antiarrhythmic: Class Overview and Comparison
Quick answer: Class III antiarrhythmic are a class of medicines used for specific therapeutic indications. iMedic covers 3 class iii antiarrhythmic substances. Below is a comparison table linking to detailed pages for each.
Class III antiarrhythmic on iMedic (3 substances)
| Substance | Primary indications | Mechanism | Common dose |
|---|---|---|---|
| Amiodarone | Ventricular arrhythmias, Atrial fibrillation | Blocks potassium channels prolonging cardiac action potential and refractory per | 200-400 mg/day oral maintenance |
| Dronedaron | Atrial fibrillation, Atrial flutter | Multichannel blocker (sodium, potassium, calcium channels) with antiadrenergic a | 400 mg twice daily |
| Dronedarone | Atrial fibrillation, Atrial flutter | Multichannel blocker (sodium, potassium, calcium channels) with antiadrenergic a | 400 mg twice daily |
About Class III antiarrhythmic
Class III antiarrhythmic share a common mechanism of action and clinical use. Specific dosing, side effects, contraindications, and drug interactions vary between individual substances within the class. Click any substance above for full prescribing information and patient guidance.
Common considerations across the class
- Indication-specific selection: Different members may be preferred for different conditions or patient populations
- Dose equivalence: Members of the same class are not always interchangeable on a 1:1 dose basis
- Drug interactions: Class members often share interaction profiles (e.g., CYP enzyme effects) but individual variation matters
- Side effects: Some side effects are class-wide; others are substance-specific
- Contraindications: Individual contraindications may not generalize across the class
Always consult the prescribing information for the specific medicine prescribed and discuss with your clinician.
Frequently asked questions
What are Class III antiarrhythmic?
Class III antiarrhythmic are medicines that share a common mechanism of action used for specific therapeutic indications. iMedic currently covers 3 substances in this class with detailed pages for each.
Are all Class III antiarrhythmic interchangeable?
No. While medicines in the same class share a mechanism, they differ in potency, dosing, drug interactions, and tolerability. Switching between them is a clinical decision based on individual response, side effects, and treatment goals.
How do I choose between different Class III antiarrhythmic?
Selection depends on the specific clinical indication, patient factors (age, comorbidities, kidney/liver function, other medications), tolerability of side effects, cost, and clinician preference. This is a prescribing decision.
Are Class III antiarrhythmic available as generics?
Most well-established class members are available as generic alternatives, often substantially less expensive than brand-name versions while clinically equivalent. Newer members may still be brand-only.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.