Drug–Device Interactions

Implantable cardioverter-defibrillators (ICDs) have demonstrated utility in the prevention of sudden cardiac death. However, a fair proportion of ICD recipients commonly present with atrial fibrillation (AF), which necessitates antiarrhythmic drug (AAD) therapy to restore/maintain sinus rhythm and prevent further exacerbation of AF, which may result from the frequent co-existence of congestive heart failure. The use of AADs as an adjunctive therapy in ICD patients presents both benefits and drawbacks. Several studies have shown that AADs can reduce the incidence of inappropriate ICD discharges by modulating arrhythmias, thereby reducing symptomology and mortality rates. In these terms, some AADs may be more effective than others. It is always important to consider safety and tolerability in AAD therapy. In addition to known risks associated with sotalol in β-blocker-refractory patients and long-term amiodarone therapy, there are adverse side effects associated with AADs that can promote ICD discharge and even prevent proper ICD functioning through poor arrhythmia detection. Interest in the role of catheter ablation in ICD therapy and/or AADs is increasing owing to promising results from recent studies. However, there are many factors to consider and the potential for drug–device interactions and the resulting clinical implications must always be considered when selecting a therapeutic regimen.