Flecainide is a narrow therapeutic index drug that requires careful patient selection and monitoring to avoid proarrhythmic effects.
There is much evidence for flecainide to be considered an NTID based on both preclinical and clinical data. A clear understanding of the potential of proarrhythmic effects or lack of efficacy, careful patient selection and regular monitoring are essential for the safe and rational administration of flecainide.
Tamargo et al. (Tue,) studied this question.