Influence of exercise on plasma concentrations of isosorbide dinitrate.

As the fall in hepatic blood flow caused by exercise is expected to decrease the elimination of high extraction drugs, the influence of exercise on the fate of the anti-anginal drug isosorbide dinitrate has been assessed. Isosorbide dinitrate 10 mg was given orally, after an overnight fast, on 2 different days to 7 healthy volunteers and the plasma concentrations of the parent compound and its mononitrate metabolites were measured. Heavy bicycle exercise from the 45th to the 105th min after intake of the drug on one of the experimental days did not change the plasma isosorbide dinitrate concentrations as compared to those on the rest day. The concentrations of both mononitrates were lower on the exercise day, but the difference was already present before the exercise started.