Blood levels of the metabolites of glyceryl trinitrate and pentaerythritol tetranitrate after administration of a two-step preparation.

Blood levels and urinary excretion rates of glyceryl trinitrate- pentaerythritol tetranitrate, and their less nitrate containing metabolites have been determined in ten human volunteers after a single dose of a two- step preparation containing glyceryl trinitrate and pentaerythritol tetranitrate. Blood levels accounted for peak levels of about 40% of the glyceryl trinitrate and 0.4% of the pentaerythritol tetranitrate metabolites, respectively. Within the first 24 h post administration 22% of the glyceryl trinitrate and 19% of the pentaerythritol tetranitrate were excreted as nitrate metabolites, chiefly in form of conjugates. The determinations were obtained by gas chromatography on extremely inactive columns and electron capture detection by means of derivatives.