What is the Vaughan Williams classification of antiarrhythmic drugs?
Vaughan Williams classification
Class | Known as | Examples |
---|---|---|
Ia | Fast-channel blockers | Quinidine Ajmaline Procainamide Disopyramide |
Ib | Lidocaine Phenytoin Mexiletine Tocainide | |
Ic | Encainide Flecainide Propafenone Moricizine | |
II | Beta-blockers | Carvedilol Propranolol Esmolol Timolol Metoprolol Atenolol Bisoprolol Nebivolol |
Which class in the Vaughan Williams classification does amiodarone belong to?
For example, amiodarone, a Class III antiarrhythmic, also has sodium and calcium-channel blocking actions.
How are groups of antiarrhythmics classified?
The antiarrhythmic medications have typically been categorized according to the Vaughan-Williams (VW) classification system. The system classifies the medications according to the primary mechanism of action (although several agents retain properties from multiple classes).
What is the Vaughan-Williams classification?
The Vaughan-Williams classification is the system used to categorize antiarrhythmic drug therapy into class IA, class IB, class IC, class II, class III, class IV and class V. See antiarrhythmic drug therapy section for specific qualities of these classes and information regarding the specific drugs.
What are the limitations of the Vaughan Williams classification?
The Vaughan-Williams classification has severe limitations. When initially conceived, there were relatively few antiarrhythmic drugs and our understanding of their mechanisms was rudimentary at best.
What was Vaughan Williams classification of calcium channel blockers?
The next reassessment of the Vaughan Williams classification was his own (1984), where he rephrased the class definitions, added calcium channel blockers, and further subdivided Class I into Ia, Ib and Ic on clinical grounds:
How are Class I drugs broken down by Vaughan Williams?
The following table shows the Vaughan-Williams classification and the basic mechanism of action associated with each class. Note that Class I drugs are further broken down into subclasses because of subtle, yet important differences in their effects on action potentials.
Which is the best classification for Antiarrhythmic Drugs?
Although different classification schemes have been proposed, the first scheme (Vaughan-Williams) is still the one that most physicians use when speaking of antiarrhythmic drugs. The following table shows the Vaughan-Williams classification and the basic mechanism of action associated with each class.