Antiarrhythmic drugs: present and future.

The treatment of cardiac arrhythmias has undergone a sea change with the advent of catheter ablative procedures (radiofrequency ablation) and use of implantable cardioverter defibrillator (ICD). The antiarrhythmic drugs at times are used to prevent device related arrhythmia rather than being used for primary treatment of arrhythmias. Antiarrhythmic drugs are grouped according to their drug action as proposed by Vaughan William or by their action on ion channels. Currently amiodarone is the most commonly used drug followed by sotalol, class II, class IV and other class III drugs. It is now well known that amiodarone has several non-cardiac toxic effects particularly on long term therapy. Efforts are on to develop newer drugs which have efficacy of amiodarone without complex pharmacokinetics and toxicity. Newer drugs like azimilide with class III action are also being developed.