Bioavailability of dihydroergosine in healthy volunteers.

Eight healthy volunteers received an oral dose of 10 mg and an intravenous dose of 0.75 mg of dihydroergosine. Plasma concentrations were measured by HPLC method, and some pharmacokinetic parameters were calculated. The biologic half-life in the elimination phase was 8.35 +/- 1.87 h after oral administration and 8.84 +/- 3.64 h after intravenous administration. In both cases of administration a secondary rise in plasma concentration of dihydroergosine was observed, which can be attributed to hepatic recycling. The calculated bioavailability of the drug was 9.80 +/- 2.8%.