Pharmacokinetics of isosorbide-5-mononitrate after oral and intravenous administration in patients with liver cirrhosis: first results.

The pharmacokinetics and bioavailability of IS-5-MN after single-dose oral and intravenous application were investigated over 24 h in three patients with liver cirrhosis and compared with normal subjects. The analysis of IS-5-MN in plasma was carried out using a gas-chromatographic method with electron capture detection. A two-compartment open model was taken as a basis for the calculations of the plasma concentration curves and the pharmacokinetic parameters. First results show that plasma concentrations after intravenous administration in the patient group were not higher than in the control group. After oral administration the peak concentrations of IS-5-MN were also no higher, nor did they occur earlier, in patients with liver cirrhosis than in the normal subjects. Our data also show the same complete absolute bioavailability of IS-5-MN in the patient group as in normal subjects, and the same elimination half-life of the plasma concentration response curve. We saw no influence of typical comedication, i.e., cimetidine or spironolactone on pharmacokinetic parameters in the group of liver patients.