Oral mexiletine in the treatment of refractory ventricular arrhythmias: the role of electrophysiologic techniques.
Mexiletine is a useful antiarrhythmic agent for the treatment of ventricular arrhythmias. Its efficacy in suppressing ventricular arrhythmias during serial electrophysiologic evaluation has come under investigation only recently. Experience to date in more than 300 patients suggests that suppression of inducible ventricular arrhythmias by mexiletine either alone or in combination with another antiarrhythmic agent may be achieved in approximately 30% of patients. Furthermore, suppression sometimes may be achieved when mexiletine is tested in combination with a type IA antiarrhythmic or beta-adrenergic blocking agent in patients for whom neither agent alone has been effective. The likelihood of suppressing inducible ventricular tachycardia (VT) with mexiletine therapy alone or in combination may vary as a function of the spontaneous ventricular arrhythmia with which a patient presents at the time of electrophysiologic study; patients presenting with sustained VT appear to have inducible arrhythmias that are more difficult to suppress. A significant incidence of adverse effects attributable to mexiletine has been observed, particularly gastrointestinal and neurologic effects. These side effects, although common, are frequently eliminated by reducing the dosage of the drug and administering the drug with food. A facilitation of arrhythmia induction has also been observed in a small percentage of patients. Early experience suggests that selected patients with ventricular arrhythmias that are refractory to conventional antiarrhythmic agents may derive long-term benefit from chronic therapy with oral mexiletine.
D000284:Administration, Oral; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D004594:Electrophysiology; D006321:Heart / Q000502:physiology; D006801:Humans; D008801:Mexiletine / Q000627:therapeutic use*; D011437:Propylamines / Q000627:therapeutic use*
D011437:Propylamines; D008801:Mexiletine