first-pass effect

first-pass metabolism

the intestinal and hepatic degradation or alteration of a drug or substance taken by mouth, after absorption, removing some of the active substance from the blood before it enters the general circulation.
Synonym(s): first-pass effect

first-pass me·tab·o·lism

, first-pass effect (fĭrst-pas mĕ-tab'ŏ-lizm, e-fekt')
The intestinal and hepatic degradation or alteration of a drug or substance taken by mouth, after absorption, removing some of the active substance from the blood before it enters the general circulation.

first-pass effect

the metabolism of orally administered drugs by gastrointestinal and hepatic enzymes, resulting in a significant reduction of the amount of unmetabolized drug reaching the systemic circulation.
References in periodicals archive ?
The nanoparticles were administered locally to the lung to prevent the first-pass effect in the liver.
The oral dispersible forms are also suited for active ingredients with a high first-pass effect and facilitate the rapid onset of action because of their quick dissolution.
This high systemic bio availability was confirmed by the mean ratio of BPAG AUC values (81 [+ or -] 18% for sublingual dosing), which is also an estimate of the systemic bioavailability, provided that the BPAG is not formed at the administration site or by a first-pass effect, which seems to be a reasonable assumption for a direct buccal absorption.
Food and Drug Administration approved dose of 10 mg has little effect on nasal decongestion when used orally because of the drug's high first-pass effect.
Because it is highly metabolized through a pronounced first-pass effect, PZQ has low effective bioavailability.
In contrast to oral administration, Dr Liu said, all of these other drug delivery routes share a common property: elimination of the first-pass effect.
Drug delivery via a spray to the oral mucosa is designed to avoid degradation in the gastrointestinal tract and metabolism by liver enzymes -- the so-called first-pass effect.
Drug delivery via a spray to the oral mucosa avoids degradation in the gastrointestinal tract and metabolism by liver enzymes -- the so-called first-pass effect.
Drug delivery via the oral mucosa avoids degradation in the gastrointestinal tract and metabolism by liver enzymes -- the so-called first-pass effect.
Drug delivery via a spray to the oral mucosa is more convenient and avoids degradation in the gastrointestinal tract and metabolism by liver enzymes -- the so-called first-pass effect.
Moreover, the local release of hormones means that gastrointestinal interference and hepatic first-pass effects are not at issue.
Transdermal delivery also avoids first-pass effects through the liver during absorption, which helps avoid drug-drug interactions.

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