This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Pharmacology
True regarding conivaptan is 
Select and explain. 
A. Vasopressin antagonist, B. V2 selective action, C. Oral drug, D. Treatment of hypernatremia
A: Vasopressin antagonist
Answer: A: Vasopressin antagonist 
Explanation: vasopressin receptor antagonists interfere with action at the vasopressin receptors. Used in the treatment of hyponatremia, especially in patients with congestive hea failure, liver cirrhosis or SIADH. EG conivaptan, tolvaptan, lixivaptan, satavaptan REF KD Tripathi 8th ed