[Methyl ether of proscillaridin]

[Effect of proscillaridin-4'-methylether on pressure rise velocity in the left ventricle of patients with coronary heart disease (author's transl)]

In a randomized, controlled, double-blind study 2 groups of 7 patients each with coronary heart disease received either 1 mg methylproscillaridin (MP) a cardiac glycoside of the squill intravenously, or placebo to test the inotropic effect of MP. Pressures and dp/dt max were measured in the left ventricle before and after coronary angiography after an average of 62 min (60 to 70 min). There was a significant (p less than 0.05) increase of dp/dt max in the MP-group (Wilcoxon-Mann-Whitney test). Left ventricular enddiastolic pressure was decreased from 16.1 to 13.6 mm Hg in the MP-group, and increased in theplacebo group from 12 to 13.7 mm Hg (mean values). Thus, a positive inotropic effect of the glycoside may be assumed.

Pharmacokinetics and pharmacodynamics of methyl proscillaridin in healthy man

The aim of this study was to obtain data about the pharmacological properties of a new glycoside derivative in man. Plasma concentrations and ECG parameters were measured after oral and intravenous administration of a single dose of 1.2 mg methyl proscillaridin in 16 healthy volunteers, using a strictly randomized, two-period change-over design. Glycoside concentrations were measured using a modified 86Rb-erythrocyte-assay. QT-duration, corrected for frequency (QTc), was the principal variable measured in the ECG. By either route, there was a maximum plasma level after 1 hour, which had decreased to a minimum at 3 hours, followed by a second peak at 4 to 10 hours (orally greater than iv). From 10 to 72 hours the concentrations decreased with a median t 1/2 of 23.3 hours (iv) and 33.0 hours (orally). Comparison of the ratio of plasma concentrations following oral and iv administration resulted in a bioavailability of 69% using the 48 hour plasma levels, and 59% using the areas under the concentration-time curves. The mean QTc was maximally shortened to 28 msec at 1 hour after iv and to 19 msec at 10 hours after the oral dose. A distinct similarity between time-concentration and time-QTc curves was seen after the initial distribution phase, both after oral and intravenous administration. The new derivative shows a rapid elimination. Its bioavailability is reasonably high.