How Do Class II Antidysrhythmics Work?

Reviewed on 5/24/2021

WHAT ARE CLASS II ANTIDYSRHYTHMICS AND HOW DO THEY WORK?

Antidysrhythmics, also known as antiarrhythmics, are drugs used to prevent abnormal cardiac rhythms such as atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation caused by improper conduction of impulses in the heart. They work by blocking sodium, potassium, and calcium channels in the heart muscles.

Antiarrhythmic drugs are grouped into four main classes: 

  • Class I, sodium-channel blockers; 
  • Class II, beta-blockers; 
  • Class III, potassium-channel blockers; 
  • Class IV, calcium-channel blockers; and 

miscellaneous antiarrhythmics or unclassified antiarrhythmics.

Class II antidysrhythmic drugs inhibit beta-adrenergic activation of adenylate cyclase and reduce sinoatrial node and atrioventricular node activity. They prolong atrioventricular node repolarization and increase the P-R interval. They decrease phase 4 (resting phase) slope in cardiac pacemaker cells and reduce conduction speed and blood pressure

Antidysrhythmic drugs do not improve the survival rate among patients with nonlife-threatening arrhythmias and may increase mortality in patients with structural heart disease.

HOW ARE CLASS II ANTIDYSRHYTHMICS USED?

Class II antidysrhythmic drugs are used to treat:

Class II antidysrhythmic drugs are used to treat:

WHAT ARE SIDE EFFECTS OF CLASS II ANTIDYSRHYTHMICS?

Common side effects include:

Serious side effects of class II antidysrhythmics include:

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

SLIDESHOW

Heart Disease: Causes of a Heart Attack See Slideshow

WHAT ARE DRUG NAMES OF CLASS II ANTIDYSRHYTHMICS?

Drug names include

References
https://reference.medscape.com/drugs/antidysrhythmics-ii

https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.118.035455

https://emedicine.medscape.com/article/2172024-overview

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