It is derived from a strain of Streptomyces aureofaciens.

It is officially indicated for the treatment of various types of bacterial infections.^[2]

Its use as an antibiotic is particularly in Lyme disease, acne and bronchitis.^{[citation needed]}

Resistance is gradually becoming more common, and demeclocycline is now rarely used for infections.

It is widely used (though off-label in many countries) in the treatment of hyponatremia (low blood sodium concentration) due to the syndrome of inappropriate antidiuretic hormone (SIADH) when fluid restriction alone has been ineffective.^[3]

The use in SIADH actually relies on a side effect; demeclocycline induces nephrogenic diabetes insipidus (dehydration due to the inability to concentrate urine).^[3] The use of demeclocycline in SIADH was first reported in 1975,^[4] and, in 1978, a larger study found it to be more effective and better tolerated than lithium carbonate, the only available treatment at the time.^[5] Demeclocycline has since been the drug of choice for treating SIADH, although it may be superseded by vasopressin receptor antagonists.