Newer aspects of the pharmacokinetics of organic nitrates.

Plasma drug and metabolite concentrations were measured after single oral doses of 40 mg sustained-release 14C-isosorbide dinitrate to humans. The bioavailability of isosorbide dinitrate from this sustained-release formulation was about 90% of that from a standard formulation. The pharmacokinetics of isosorbide-5-mononitrate were studied in humans after intravenous infusion (8 mg/h) and oral doses of 20 mg. The systemic availability of the drug after oral doses was 93%, its systemic clearance was 127 ml/min, its volume of distribution was 48.5 liters and its half-life was 4.4 h.