[A nondepolarizing muscle relaxant with rapidly developing and short-term action]

The pharmacological properties of the new nondepolarizing myorelaxant IEM-1213 and of its mixture with tercuronium were studied in experiments on anesthetized cats. Intravenous infusion of a blocking dose of IEM-1213 did not cause a change in the level of arterial pressure and blockade of the sympathetic ganglia but induced blockade of the heart muscarine receptors. The effect of IEM-1213 develops more rapidly and lasts for a shorter time than that of dithylin. Intravenous infusion of a mixture of IEM-1213 and tercuronium constituting 35 and 60% of the blocking dose of the former and, respectively, 35 and 20% of the blocking dose of the latter causes an effect similar in the time of its development to that of intravenous infusion of a total dose of IEM-1213 alone.