Flecainide-induced myalgias and weakness: a rare adverse reaction.

Dilpat Kumar, Muhammad Ebad Rehman, Tracey Mersfelder, Prashant Patel

BMJ case reports 2021 Apr 15

filter terms:

Flecainide is a class 1C antiarrhythmic, which is known to cause several cardiac and non-cardiac adverse reactions. We report a case of a 62-year-old woman with atrial fibrillation who presented with generalised myalgias and intermittent chest heaviness after being started on flecainide. She had undergone her third cardiac ablation 1 week prior to presentation and was subsequently started on flecainide 150 mg two times per day. On physical examination, she had diminished reflexes and diffuse calf tenderness. Her blood tests demonstrated an increased erythrocyte sedimentation rate and C reactive protein, but otherwise normal infectious and autoimmune labs. Her ECG showed normal sinus rhythm. A Naranjo score of 7 suggested flecainide as a probable cause of her myalgias. The patient's symptoms started to normalise within 24 hours of discontinuation of flecainide. Our case highlights that myalgias are a potential rare adverse effect that should be considered in patients prescribed flecainide. © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.

Citation

Dilpat Kumar, Muhammad Ebad Rehman, Tracey Mersfelder, Prashant Patel. Flecainide-induced myalgias and weakness: a rare adverse reaction. BMJ case reports. 2021 Apr 15;14(4)