Demeclocycline hydrochloride is a tetracycline antibiotic primarily used to treat various bacterial infections. It is effective against a range of bacteria, including those causing respiratory tract infections, urinary tract infections, and skin infections. Additionally, it is sometimes prescribed for the treatment of acne due to its ability to reduce inflammation and bacterial growth.

In a non-antibiotic capacity, demeclocycline hydrochloride is utilized in the management of Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH). It works by inducing a form of nephrogenic diabetes insipidus, which helps to correct the imbalance of water and electrolytes in the body.

The compound is also employed in veterinary medicine to treat bacterial infections in animals. Its broad-spectrum antibacterial properties make it a versatile option for both human and animal healthcare.