Gastric excretion of intravenously administered meperidine in surgical patients

Area of Science:

• Pharmacology
• Gastroenterology
• Drug Metabolism

Background:

• Meperidine (also known as pethidine) is an opioid analgesic.
• Understanding drug distribution and concentration in different bodily fluids is crucial for pharmacokinetics.
• Gastric juice pH can influence the absorption and distribution of certain medications.

Purpose of the Study:

• To investigate the concentration and behavior of unchanged meperidine in human gastric juice after intravenous administration.
• To determine the rate of meperidine appearance in gastric contents.
• To elucidate the mechanism behind any observed sequestration.

Main Methods:

• Intravenous administration of meperidine to human subjects.
• Sampling of gastric juice at specific time points post-administration.
• Analysis of meperidine concentrations in gastric juice and plasma using validated analytical techniques.

Main Results:

• Significant sequestration of unchanged meperidine was observed in gastric juice.
• Gastric juice concentrations were up to 360 times higher than concurrent plasma concentrations.
• Meperidine was detected in gastric juice as early as 5 to 15 minutes after intravenous injection.

Conclusions:

• The study demonstrates a pronounced sequestration of meperidine in the stomach.
• The observed phenomenon is attributed to the ionization and subsequent ion trapping of meperidine within the acidic environment of gastric juice.
• This finding has implications for understanding meperidine pharmacokinetics and potential drug interactions.