First-Pass Effect

Định nghĩa

The phenomenon where an orally administered drug is significantly metabolized by the liver before reaching systemic circulation. This reduces the amount of active drug available to the body and is a major reason why oral doses are often higher than intravenous doses of the same drug.

Ví dụ

Nitroglycerin undergoes extensive first-pass metabolism, which is why it's given sublingually (under the tongue) rather than swallowed.

Thuật ngữ liên quan

Bioavailability F Clearance CL Sublingual SL

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