Last reviewed 01/2018

Demeclocycline is a tetracyline drug used in the treatment of hyponatraemia caused by syndrome of inappropriate ADH secretion, where fluid restriction has not been effective.

It may act to directly block the action of ADH on the tubule; in doing so it effectively causes a nephrogenic diabetes insipidus.

Side effects include diabetes insipidus and a photosensitive rash.

Demeclocycline can cause reversible azotaemia and sometimes nephrotoxicity, especially in patients with cirrhosis


  • (1) hyponatraemia Treatment Guidelines 2007: Expert Panel Recommendations.American Journal of Medicine 2007; 120 (11);S1:S1-S21.