Propylene glycol pharmacokinetics and effects after intravenous infusion in humans

Knowledge of the pharmacokinetics of propylene glycol (PG) is scarce, though it is used in a number of preparations for intravenous use. Although systemic toxicity appears to be uncommon, PG has been reported to cause lactic acidosis and other adverse effects. We describe a rapid gas chromatographic assay method for PG and the plasma pharmacokinetics after intravenous administration to six patients on nine occasions. The pharmacokinetics were nonlinear, based on a saturable clearance. The apparent first-order half-life was 2.3 +/- 0.7 h. There was no evidence of lactic acidosis, hemolysis, or increase in osmolality at 3-15 g/m2 PG infused over periods of 4 h.