Phenytoin: an old but effective antiarrhythmic agent for the suppression of ventricular tachycardia

Lessons from Practicehenytoin, a widely used anticonvulsant, has class IB antiarrhythmic drug (AAD) properties, and is a potential option for patients with refractory ventricular arrhythmia when other agents are contraindicated or unavailable.In patients with frequent ventricular arrhythmia, AADs are often used to reduce the frequency of arrhythmia and implantable cardioverter defibrillator (ICD) shocks.Amiodarone is often used as first-line therapy.Although class I AADs are generally not pre-scribed for patients with ischaemic heart disease or cardiomyopathy, they are occasionally used in combination with amiodarone in patients who are refractory to amiodarone monotherapy, especially those with ICDs, as this provides some protection against potential proarrhythmic side effects. 1 Phenytoin has class IB antiarrhythmic properties due to its effects on sodium channels in cardiac myocyte and Purkinje fibre cell membranes. 2It reduces the maximum Phenytoin: an old but effective antiarrhythmic agent for the suppression of ventricular tachycardia