first-pass metabolism n. a process in which a drug administered by mouth is absorbed from the gastrointestinal tract and transported via the portal vein to the liver, where it is metabolized. As a result, in some cases only a small proportion of the active drug reaches the systemic circulation and its intended target tissue. First-pass metabolism can be bypassed by giving the drug via. Jul 28, · The first pass effect is a phenomenon in which a drug gets metabolized at a specific location in the body that results in a reduced concentration of the active drug upon reaching its site of action or the systemic circulation. The first pass effect is often associated with the liver, as this is a ma Author: Timothy F. Herman, Cynthia Santos. First-pass elimination takes place when a drug is metabolised between its site of administration and the site of sampling for measurement of drug concentration. Clinically, first-pass metabolism is important when the fraction of the dose administered that escapes metabolism is small and variable. Th .
The application of basic pharmacokinetic concepts, e. First Virginia Banks, Inc. Tam YK. Firstborn Children. The hepatic first-pass metabolism of problematic drugs. Unfortunately, a major drawback of Invirase meetabolism its limited bioavailability due to incomplete absorption and extensive first-pass metabolism. Firth, Julian.
Alcohol Alcohol Suppl. Alcohol Clin Exp Res. First Pass Effect. Retrieved January 24, from Encyclopedia. Wilkinson GR. Nasal Drug Delivery System. Here metabolism of a substance that occurs immediately as it enters the body, and before it can exert any effect, or before it can be measured at its target organ. J Ethnopharmacol.