A patient with syndrome of inappropriate antidiuretic hormone secretion is started on a tetracycline that antagonizes vasopressin at the collecting duct. Which agent was chosen?

• A Minocycline
• B Tigecycline
• C Tetracycline
• D Demeclocycline ✓

Explanation

Demeclocycline reliably induces a state resembling nephrogenic diabetes insipidus by blocking ADH action on the collecting duct epithelium. This side effect has been deliberately exploited to manage chronic hyponatremia of SIADH when fluid restriction fails, though onset takes several days. Minocycline and tetracycline do not produce this effect clinically, and tigecycline is a glycylcycline reserved for serious multidrug-resistant infections.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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