Flecainide Induced Myoclonus and Severe Asthenia Necessitating Intensive Care Unit Management and Intubation: A Case Report.

Flecainide is class Ic antiarrhythmic drug with a narrow therapeutic range. Adverse drug reactions during flecainide therapy are predominately cardiac in nature. Severe neurological adverse drug reactions have rarely been described. We describe the case of a 71-year-old female who developed myoclonus and severe asthenia requiring intubation and management in the neuroscience intensive care unit. Immediate discontinuation of flecainide and supportive care to allow for drug elimination was the primary treatment. Resolution of flecainide neurotoxicity resolved after 5 days of stopping flecainide. Clinicians should be cognizant of potential neurologic toxicity of flecainide.