Question:medium
Which second generation antihistaminic does NOT produce an active metabolite?
Which second generation antihistaminic does NOT produce an active metabolite?
Show Hint
It is the active metabolite of hydroxyzine and is not converted further.
Updated On: Jun 24, 2026
- Loratadine
- Terfenadine
- Cetirizine
- None
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: The trick is to recall which low-sedating antihistamines are essentially their own end-product and which depend on hepatic conversion for their effect.
Step 2: Terfenadine is a classic prodrug whose activity comes from fexofenadine formed in the liver, and loratadine relies heavily on desloratadine for its long action. Each of these therefore creates an active metabolite, ruling out (a) and (b).
Step 3: Cetirizine stands apart because it is already the active acid derivative of hydroxyzine and undergoes minimal further metabolism. It clears largely unchanged in the urine, so no fresh active metabolite is produced.
Step 4: Since cetirizine clearly satisfies the requirement, the answer cannot be None, eliminating (d).
\[\boxed{\text{Cetirizine}}\]
Step 2: Terfenadine is a classic prodrug whose activity comes from fexofenadine formed in the liver, and loratadine relies heavily on desloratadine for its long action. Each of these therefore creates an active metabolite, ruling out (a) and (b).
Step 3: Cetirizine stands apart because it is already the active acid derivative of hydroxyzine and undergoes minimal further metabolism. It clears largely unchanged in the urine, so no fresh active metabolite is produced.
Step 4: Since cetirizine clearly satisfies the requirement, the answer cannot be None, eliminating (d).
\[\boxed{\text{Cetirizine}}\]
Was this answer helpful?
0
