2597 Flecainide A potent anti-arrhythmia agent, effective in a wide range of ventricular and atrial arrhythmias and tachycardias. Paradoxically, however, in myocardial infarct patients with either symptomatic or asymptomatic arrhythmia, flecainide exacerbates the arrhythmia and is not recommended for use in these patients. [PubChem] 54143-55-4 3356 C17H20F6N2O3 414.137810 Solid (A308). 228-229°C 48.4 mg/mL at 37°C (acetate form) Ingestion (MSDS, A308). Nearly complete following oral administration. Flecainide acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers. Flecainide is a sodium channel blocker, binding to voltage gated sodium channels. It stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. Hepatic. Flecainide does not undergo any consequential presystemic biotransformation. The two major urinary metabolites are meta-O-dealkylated flecainide (active, but about one-fifth as potent) and the meta-O-dealkylated lactam of flecainide (non-active metabolite). The absoprtion is nearly complete following oral administration. Hepatic. Flecainide does not undergo any consequential presystemic biotransformation. The two major urinary metabolites are meta-O-dealkylated flecainide (active, but about one-fifth as potent) and the meta-O-dealkylated lactam of flecainide (non-active metabolite). Route of Elimination: In healthy subjects, about 30% of a single oral dose (range, 10 to 50%) is excreted in urine as unchanged drug. Several minor metabolites (3% of the dose or less) are also found in urine; only 5% of an oral dose is excreted in feces. In patients, free (unconjugated) plasma levels of the two major metabolites are very low (less than 0.05 ug/mL). Half Life: 20 hours (range 12-27 hours) LD50: 50-498 mg/kg (Oral, Rat) (A308) No indication of carcinogenicity to humans (not listed by IARC). Flecainide is is a class Ic antiarrhythmic agent and as such, it is used for the prevention of paroxysmal supraventricular tachycardias (PSVT), including atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia and other supraventricular tachycardias of unspecified mechanism associated with disablin (A308). Signs of flecainide toxicity include marked prolongation of the PR interval and widening of the QRS duration on the surface ECG. There may be signs and symptoms attributable to overt heart failure secondary to sudden decreased myocardial contractility (L1129). Symptoms of overdose include nausea and vomiting, convulsions, hypotension, bradycardia, syncope, extreme widening of the QRS complex, widening of the QT interval, widening of the PR interval, ventricular tachycardia, AV nodal block, asystole, bundle branch block, cardiac failure, and cardiac arrest. Treatment of flecainide toxicity involves increasing the excretion of flecainide, blocking its effects in the heart, and (rarely) institution of cardiovascular support to avoid impending lethal arrhythmias. Modalities that have had success include administration of a beta-sympathomimetic agent, and administration of a sodium load (often in the form of hypertonic sodium bicarbonate). Placing the individual on cardiopulmonary bypass support may be necessary in order to temporarily obviate the need for a beating heart and to increase blood flow to the liver. (L1129) 2009-07-05T02:56:03Z 2014-12-24T20:25:41Z Cytochrome P450 2D6 (CYP2D6) (P10635) (A308) Flecainide C07001 127588 Flecainide DB01195 true Cytochrome P450 2D6 (P10635) (A308) OC(=NCC1CCCCN1)C1=C(OCC(F)(F)F)C=CC(OCC(F)(F)F)=C1 C17H20F6N2O3 InChI=1/C17H20F6N2O3/c18-16(19,20)9-27-12-4-5-14(28-10-17(21,22)23)13(7-12)15(26)25-8-11-3-1-2-6-24-11/h4-5,7,11,24H,1-3,6,8-10H2,(H,25,26) InChIKey=DJBNUMBKLMJRSA-UHFFFAOYNA-N 414.3427 414.137811746 Exogenous Solid 3.78 HMDB15326 CHEMBL652 3239 <p>Bmitt, E.H. and Brown, W.R.; U.S. Patent 3,900,481; August 19,1975; assigned to Riker Laboratories, Inc.</p>