Isosorbide dinitrate in plasma and dialysate during haemodialysis

In 10 patients with end stage renal disease on regular haemodialysis the plasma concentrations and dialyzer clearance of isosorbide dinitrate (ISDN) were determined after an oral dose of a retarded release formulation of 60 mg ISDN. The maximal plasma concentration of ISDN 2-7 h after oral administration was higher (14 ng/ml) than has been reported in healthy volunteers. The haemodialyzer clearance of ISDN was 92.4 ml/min at a blood flow of 200 ml/min and dialysate flow of 500 ml/min. During a 5-h haemodialysis an average of 0.3 mg ISDN was removed from the patient's circulation, representing about 0.5% of the administered dose and about 3% of the available drug in the circulation. No influence of haemodialysis on the plasma level of ISDN was found.