Interaksi Meksiletin dan Propafenon

• The applicability of the CAST results to other populations (e.g., those without recent myocardial infarction) or other antiarrhythmic drugs is uncertain, but at present, it is prudent to consider any IC antiarrhythmic to have a significant proarrhythmic risk in patients with structural heart disease.

• Avoid use with other antiarrhythmic agents or drugs that prolong the QT interval.

Concurrent use of propafenone with other antiarrhythmic agents has not been well studied.

Considering the known proarrhythmic properties of mexiletine and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of mexiletine as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmia.

In this crossover steady state study, the pharmacokinetics of propafenone were unaffected in either phenotype by the coadministration of mexiletine.

Addition of mexiletine to propafenone did not lead to further electrocardiographic parameters changes of QRS, QT C , RR, and PR intervals than propafenone alone.

In another formal study (n = 8 extensive and n = 7 poor metabolizers of CYP2D6), coadministration of propafenone did not alter the kinetics of mexiletine in the poor CYP2D6 metabolizer group.