first-pass metabolism

(redirected from First pass effect)
Also found in: Wikipedia.

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 metabolism

The 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.
See also: metabolism
References in periodicals archive ?
009% in feces), which might be resulted from liver first pass effect.
Therefore, liver first pass effect is one of the exact reasons to explain this fact.
Low recoveries of Pd-la in bile, urine and feces indicated that few intact form of Pd-la was excreted by bile and kidney, which might be resulted from liver first pass effect.
For example, if the route is ingestion, much of the chlorpyrifos may be metabolized to TCPy in the first pass effect before chlorpyrifos reaches the maternal systemic blood supply and hence the placenta (Figure 2).
Further study is needed to help determine if transdermal administration of estrogen therapy has the same effect on biliary tract outcomes, since the first pass effect would be lessened," they noted.
The pills can be taken within 12 hours, and are easier than vaginal administration, avoid the first pass effect through the liver as in oral administration, and offer more privacy during the process.
Budesonide has topical anti-inflammatory activity and due to an extended first pass effect, has less systemic absorption than other corticosteroids.
Full browser ?