[Threshold of action of meproscillarin following intravenous administration]

A placebo-controlled double-blind trial was conducted, to determine the onset of effect of Meproscillarin (injected intravenously). 28 days apart six healthy volunteers were given double-blind 1,0 mg Meproscillarin or placebo and 60 days later 0,6 mg Digoxin, each drug as short infusion over four minutes. The total electromechanical systole corrected for heart rate (QS2c), was used as criterion of the inotropic effect of the glycoside. After placebo there no changes were observed over a period of two hours. Both glycosides shortened QS2c for about--16 ms. From Meproscillarin a 40% higher dosis was required, to achieve the same effect as with digoxin. After use of Meproscillarin the peak effect was reached after ten minutes; after digoxin a period of 60--120 minutes were required. The results show that intravenously given Meproscillarin is a fast acting glycoside.