Primary and secondary detoxification in severe flecainide intoxication

Abstract

Since experience with primary and secondary detoxification in severe flecainide intoxications is limited, 2 different cases of flecainide intoxications are reported. In the first case, with plasma concentrations of 6500 ng/ml (therapeutic range: 200-980 ng/ml), the patient survived with a pacemaker and catecholamine support. In the second case, hemoperfusion terminated the need for emergency resuscitation during the initial phase, but was unsuccessful 3 h later. Even with a lower plasma concentration the patient died. Both patients had rapid onset of symptoms due to the very good bioavailability of the drug. Although it may be a rare intoxication, it is dangerous because of its quick onset and its efficiency in altering the cardiac stability. We recommend the prophylactic use of a pacemaker and gastric suction. The usefulness of hemoperfusion has not yet been proven.

Fatal flecainide intoxication.

“…A similar deterioration to ventricular fibrillation has been reported 70 hours after ingestion. 6 The plasma flecainide concentration at 73 hours in this patient was 0.7 mg/l having been 6.5 mg/l three hours after ingestion. This patient however, responded to a single defibrillatory shock.…”

Successful treatment of flecainide overdose with sustained mechanical circulatory support

“…Flecainide causes rate-dependent slowing of the fast sodium current I Na during phase 0 of the cardiac action potential as well as inhibition of the rectifier potassium current I Kr during phase 3 2, 3, 4. Flecainide overdose is difficult to treat because of the drug’s high oral bioavailability (90%), high volume of distribution (8–9 L/kg), long half- life (up to 23 hours), poor ability to be dialyzed, lack of an antidote, and rapid onset of shock and arrhythmias (as early as 30 minutes after ingestion) 1, 5, 6…”

“…Initial management consists of careful monitoring of vital signs, telemetry, aggressive IV fluids, repletion of electrolytes, and admission to the intensive care unit. Because of flecainide’s high oral bioavailability, treatment may include gastric lavage if the patient presents within 1 hour of ingestion and activated charcoal regardless of the time to presentation 1, 6. Our patient did not receive gastric lavage because she presented to our hospital more than 1 hour after ingestion.…”

Life-Threatening Flecainide Intoxication in a Young Child Secondary to Medication Error

“…[13][14][15][16] The sodium load is thought to overcome the sodium blockade and reverse QRS prolongation. 4 Theoretically, hypertonic sodium chloride would have the same result, with the advantage of avoiding alkalinization with resultant delayed renal clearance, although this remains unproven.…”