Successful Use of Lidocaine in the Management of Severe Flécaïne Poisoning Refractory to Conventional Treatment

Introduction: Intoxications with class Ic antiarrhythmics, such as flécaïne, are rare but potentially life-threatening. We report a case of severe flécaïne poisoning where the use of lidocaine, a class Ib antiarrhythmic, enabled effective management of refractory rhythm disturbances. Methods: A 22-year-old female patient was admitted for voluntary flécaïne poisoning after ingesting 2 g. She presented with shock, ventricular fibrillation, and torsades de pointes refractory to conventional treatment (cardioversion, magnesium sulfate, bicarbonates, amiodarone). Results: After initial treatment failure, a lidocaine loading dose successfully resolved refractory ventricular rhythm disturbances. Continuous administration of lidocaine subsequently stabilized the patient's hemodynamic status and reduced the need for vasopressors. Discussion: While the use of lidocaine is traditionally contraindicated in poisoning with class Ic antiarrhythmics due to the risk of drug interactions, this case demonstrates its potential value in refractory situations. Lidocaine may have a competitive effect on sodium channels, thereby reversing the toxicity of potent inhibitors such as flécaïne. Conclusion: In severe flécaïne poisoning refractory to conventional treatment, the use of lidocaine can be a life-saving therapeutic option when extracorporeal clearance techniques are not available.