Used as an antiarrhythmic agent to treat various types of cardiac arrhythmias, particularly ventricular arrhythmias. It works by blocking sodium channels in the heart, which helps stabilize abnormal electrical activity and restore normal heart rhythm. Due to its moderate lipophilicity, it crosses the blood-brain barrier and may cause central nervous system side effects, which influences its clinical use. Primarily prescribed when other antiarrhythmic drugs are ineffective or not tolerated.