- Flecainide PO 50 -200 mg BID (or 300 mg as pill in the pocket)
Distribution and metabolism
- 5-7 days may be required to reach steady state in some patients
- 85% of the drug is unchanged, but its two major metabolites have less antiarrhythmic potency than the parent drug
- CYP2D6 deficiency results in impaired metabolism
Therapeutic drug monitoring
- Can obtain levels 5-7 days after steady state has been reached
- QRS prolongation with stress is most usually used for monitoring
Therapeutic plasma concentrations
- 0.2-1.0 mcg/mL
- Renally excreted, can decrease dose in chronic kidney disease
- Congestive heart failure can increase levels, although not recommended in congestive heart failure
- Zipes, et al. Braunwald’s Heart Disease, A Textbook of Cardiovascular Medicine, 11 th edition, Chapter 36, Therapy of Cardiac Arrhythmias.
- Campbell TJ, Williams KM. Therapeutic drug monitoring: antiarrhythmic drugs. J Clinical Pharmacol. 2001;52:21S-35S.