Question

First pass metabolism occurs mainly in _______

• A. Kidney
• B. Liver
• C. Lungs
• D. Skin

Hint:

First pass metabolism mainly occurs in the liver and can reduce the bioavailability of orally administered drugs.

Answer 1

The Correct Option is B

Concept:
First pass metabolism is the metabolism of a drug before it reaches the systemic circulation.

Step 1: After oral administration, a drug is absorbed from the gastrointestinal tract.

Step 2: The absorbed drug enters the portal circulation.

Step 3: The portal circulation carries the drug to the liver.

Step 4: In the liver, enzymes may metabolize a large amount of the drug before it reaches the general circulation.

Step 5: Therefore, first pass metabolism occurs mainly in the liver. \[ \boxed{\text{Liver}} \]