Fatal intoxication by tocainide.
A 26-year-old woman committed suicide by ingestion of a large quantity of tocainide, a recently developed oral antiarrhythmic agent with chemical similarities to lidocaine. Blood and bodily fluid analysis by thin-layer chromatography, high pressure liquid chromatography, and mass spectroscopy confirmed the presence of tocainide, with a serum level of 68 mg/L, nearly 7 times the upper recommended therapeutic level for this drug. Tocainide was also detected at significant levels in vitreous fluid and bile. Although the mechanism of death from tocainide intoxication in animal studies is related to central nervous system toxicity, the presentation of ventricular tachyarrhythmias with coma in this patient suggests that tocainide at high levels may have primary myocardiotoxicity in humans.