A pharmaceutical composition comprising lidocaine N-oxide (LNO), or a pharmaceutically acceptable salt thereof is provided, for use in a prophylactic treatment to prevent, or decrease the likelihood of, sudden cardiac death associated with ventricular fibrillation (VF) in a subject, whereby the composition is provided to the subject’s blood stream via the oral mucous membrane or via pulmonary absorption in the lungs or by IV administration. The treatment preferably decreases the chance of occurrence of VF and/or reduces the severity of VF.
