Plasma prostaglandin E1 concentrations and hemodynamics during intravenous infusions of prostaglandin E1 in humans and swine.

Abstract Prostaglandin (PG) E1 administered intravenously has been used for the treatment of primary nonfunction of hepatic allografts and fulminant hepatic failure. It has been proposed that this therapy may improve hepatic blood flow via the vasodilating properties of PGE1. However, PGE1 undergoes extensive metabolic inactivation by the lung and the concentration of PGE1 reaching the liver during intravenous administration has not been determined. Thus, we measured plasma PGE1 concentrations in patients with hepatic dysfunction being treated with PGE1 and in a swine model of PGE1 infusion. We also determined the hemodynamic effects of PGE1 infusion in swine. Blood was sampled from the pulmonary artery, carotid artery, portal vein, and hepatic vein in swine infused with PGE1 (range, 0.67-4.9 microg/kg/hr) demonstrating: (1) a pulmonary extraction ratio of PGE1 of 0.78 +/- 0.12, (2) a splanchnic extraction ratio of PGE1 of 0.54 +/- 0.23, and (3) levels of PGE1 in the systemic circulation of hepatic dysfunction (0.11-1.30 microg/kg/hr) had a pulmonary extraction ratio of 0.69 +/- 0.17. Systemic arterial concentrations of PGE1 were splanchnic circulations, current clinical protocols for intravenous administration of PGE1 are not likely to affect perihepatic hemodynamics.