Saliva concentrations of isosorbide dinitrate, isosorbide 2-mononitrate and isosorbide 5-mononitrate

Correlations between saliva and plasma concentrations of isosorbide dinitrate (ISDN), and its active metabolites, isosorbide 2-mononitrate (2-ISMN) and isosorbide 5-mononitrate (5-ISMN) were examined. In the case of 5-ISMN (r = 0.98, P less than 0.01), saliva concentrations are probably reliable indices of the plasma concentrations of this drug and their measurement should provide a useful non-invasive procedure to assess compliance during the clinical use of products containing either ISDN or 5-ISMN: it may also be helpful in assessing the clinical pharmacokinetics of 5-ISMN. Less satisfactory correlations were obtained for ISDN (r = 0.84) and 2-ISMN (r = 0.83).