Question:easy
Which of the following drugs is used in SIADH (syndrome of inappropriate ADH secretion)?
Which of the following drugs is used in SIADH (syndrome of inappropriate ADH secretion)?
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Block the V2 receptor to dump free water; pick the vaptan.
Updated On: Jun 23, 2026
- Tolvaptan
- Desmopressin
- von Willebrand factor
- Terlipressin
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: Reduce SIADH to one idea: too much ADH effect, so you need to block the V2 receptor and let water out.
Step 2: Tolvaptan is the non-peptide V2 antagonist taken once daily, metabolized by CYP3A4. By promoting an aquaresis (water loss without sodium loss) it raises serum sodium toward normal.
Step 3: Desmopressin and terlipressin push the receptor the other way as agonists, so they aggravate hyponatremia and are used for diabetes insipidus or variceal bleeding instead. von Willebrand factor belongs to hemostasis, not water balance.
Step 4: The only V2 blocker offered, and therefore the SIADH drug, is clear.
\[\boxed{\text{Tolvaptan}}\]
Step 2: Tolvaptan is the non-peptide V2 antagonist taken once daily, metabolized by CYP3A4. By promoting an aquaresis (water loss without sodium loss) it raises serum sodium toward normal.
Step 3: Desmopressin and terlipressin push the receptor the other way as agonists, so they aggravate hyponatremia and are used for diabetes insipidus or variceal bleeding instead. von Willebrand factor belongs to hemostasis, not water balance.
Step 4: The only V2 blocker offered, and therefore the SIADH drug, is clear.
\[\boxed{\text{Tolvaptan}}\]
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