The activity of alaglyzin, a new drug based on a clathrate complex of allapinine (well-known antiarrhythmic) with glycyrrhizic acid (GA), was studied on the models of arrhythmia induced by itraperitoneal injections of calcium chloride (CaCl2) and adrenaline (epinephrine) in rats. Alaglyzin is less toxic than allapinine (LD50 70 and 6 mg/kg, respectively), and the effective dose of the parent compound in the complex form is also about 12 times lower than that in the reference drug. The experiments showed a dose dependent action of alaglyzin. Pretreatment of the experimental animals with alaglyzin in a dose of 0.25 mg/kg prevented from the arrhythmia development in both tests, while a dose of 0.125 mg/kg was effective only in the CaCl2, test.