Gastric excretion of intravenously administered meperidine in surgical patients.

We have demonstrated sequestration of unchanged meperidine in gastric juice of humans following intravenous administration. Concentrations attained were as great as 360 times plasma concentration. The drug was first detected between 5 and 15 minutes after administration. This phenomenon appears to be due to ionization and ion trapping of meperidine in gastric juice.