A Focus on the Synthesis and Pharmacokinetics of Tocainide and its Analogues

Tocainide is an antiarrhythmic agent belonging to class IB that was primarily used for suppression of symptomatic ventricular arrhythmias. Tocainide was also reported to relieve pain such as tic douloureux, trigemina neuralgia in humans and tinnitus. Significant antinociception, as assayed on the hot-plate test, was observed after intraperitoneal injection of tocainide, too. By the mid-1980s tocainide was emerging as a more consistently effective treatment for myotonic disorders. Numerous reports of serious adverse reactions led to the use of tocainide being discontinued, even though research on tocainide and its analogues, endowed with a better pharmacological profile, is still in progress for their potential usefulness in the treatment of myotonias. This review is focused on the description of the different synthetic routes to racemic and optically active tocainide developed in the last decades, as well as analytical studies regarding enantioseparation methods. Finally, some analogues of tocainide reported in the literature, most of which with pharmacological studies, have been mentioned.