first-pass effect

https://doi.org/10.1351/goldbook.FT06824
@[email protected] and, in some cases, @[email protected] of a substance in the liver after absorption from the intestine and before it reaches the @[email protected] circulation.
Source:
PAC, 2004, 76, 1033. (Glossary of terms used in toxicokinetics (IUPAC Recommendations 2003)) on page 1052 [Terms] [Paper]