Abstract
The comparison of three thiamine derivatives, thiamine hydrochloride (B_1), thiamine tetrahydrofurfuryldisulfide (TTFD) and thiamine diphosphate (TDP), was made using Vagus amine test in guinea pig under urethane anesthesia. The rapid injection of these thiamine derivatives induced ventricular arrhythmia, except in case of large dose of TTFD. These arrhythmias were based on catecholamine, released mainly from the reserpine depletable store and the guanoxan inhibitable, but still the direct action of thiamine existed. The degree of bradycardia suppression during vagal stimulation after rapid injection was stronger than the non-injected, according to the dosage increase of B_1 and TTFD. No difference was observed between B_1 and TTFD in the mean value of antiarrhythmic potency, but the percentage of effectiveness was larger and standard error of TTFD was smaller than those of B_1. Clinically, 50 mg of TTFD suppressed at least 45% of ventricular arrhythmia, and this action was more apparent in the patients with shorter history of arrythmia.
