Group III antiarrhythmics

What are Group III antiarrhythmics?

Group III antiarrhythmics: Potassium-channel blockers, bind to and block the potassium channels which prolongs repolarization of the cell membrane.

Class III agents include: bretylium, amiodarone, ibutilide, sotalol, dofetilide, vernakalant, and dronedarone.

This class of drugs is developed for treatment of both supraventricular and ventricular arrhythmias. Amiodarone, sotalol, dofetilide, and ibutilide are examples of class III drugs that are currently available.

Of the Class III antiarrhythmics, amiodarone is involved in a significant number of interactions since it is a potent inhibitor of several cytochrome P450 enzymes. It can significantly impair the metabolism of digoxin, theophylline and warfarin.

Controlled substances categorized under Penalty Group 3 are prescription only stimulant or depressant narcotics that have the potential for addiction. The most common controlled substances categorized under Penalty Group 3 are: Anabolic Steroids. Benzodiazepines.

Class III devices “usually sustain or support life, are implanted, or present potential unreasonable risk of illness or injury.” Only 10% of medical devices marketed in the U.S. fall under this category. Examples of Class III devices include: Pacemakers. Implanted prosthetics. Cochlear implants.