First-pass effect

The first-pass effect refers to the process where a drug isbroken down and reduced in strength by the liver before it reaches the rest of thebody. When you take medication orally, it travels from your stomachand intestines to the liver via the portal vein. The liver then metabolizespart of the drug, which can decrease the amount that enters your bloodstreamand reaches targeted tissues. This process can influence how much medicationis available to be effective, often leading doctors to adjust dosages orchoose alternative delivery methods to ensure the medication worksproperly.