Which of the following is the drug of choice for the treatment of inappropriate anti-diuretic hormone secretion-

Ans. is 'd' i.e., Demeclocycline The drug most commonly used to t/t hyponatremia in syndrome of inappropriate ADH secretion is Demeclocycline.Demeclocycline is a tetracycline and is used in the t/t of chronic hyponatremia due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) when water restriction therapy has failed.Demeclocycline produces a state of unresponsiveness to ADH, probably by inhibiting the formation and action of cyclic AMP in the renal tubule.It is effective and convenient to use in SIADH because this action is both dose-dependent and reversible.Role of Frusemide in SIADHSIADH may be treated with frusemide if there is a dangerous degree of volume overload.Also go through the following text from Harrison which discusses the future drug therapy for SIADH."One or more nonpeptide AVP antagonists that block the antidiuretic effect of AVP may soon be approved for use in United States. Preliminary studies with these antagonists in acute or chronic SIADH indicate that they produce a dose dependent increase in urinary free water excretion, which, if combined with a modest restriction of fluid intake, gradually reduces body water and corrects the hyponatremia without any recognized adverse effect. Thus they may become the t/t of choice for those forms of SIADH in which there is inappropriate secretion of AVP that cannot be corrected by other more specific therapy