ANTIARRYTHMIC DRUGS

Class		Examples	Mechanism
Ia	fast-channel blockers-affect QRS complex	Quinidine Procainamide Disopyramide	(Na+) channel block (intermediate association/dissociation) and K+ channel blocking effect
Ib	Can prolong QRS in overdose	Lidocaine Phenytoin Mexiletine Tocainide	Na+ channel block (fast association/dissociation)
Ic		Flecainide Propafenone Moricizine	Na+ channel block (slow association/dissociation)
II	Beta-blockers	Carvedilol Propranolol Esmolol Timolol Metoprolol Atenolol Bisoprolol	Beta blocking Propranolol also shows some class I action
III		Amiodarone Sotalol Ibutilide Dofetilide Dronedarone	K+ channel blocker Sotalol is also a beta blocker[3]Amiodarone has Class I, II, III & IV activity
IV	Slow-channel blockers	Verapamil Diltiazem	Ca2+ channel blocker
V		Adenosine Digoxin Magnesium Sulfate	Work by other or unknown mechanisms (direct nodal inhibition)

THERE ARE MAINLY 4 CLASSES OF ANTIARRYTHMIC DRUGS