Demecycline is a tetracycline antibiotic drug. Tetracyclines have a broad spectrum of anti-microbial activity and act by interfering with bacterial protein synthesis. Demecycline is used to treat a wide range of infections caused by bacteria. Some of these infections are: Severe acne; Infections of the brain and liver caused by the bacteria Leptospira; Infection caused by Brucella bacteria (brucellosis); Infections caused by Rickettsiae micro-organisms transmitted by lice, fleas, ticks and mites; Infections of the sex organs and organs associated with urination (genito-urinary infections) such as an infection called chancroid, non-gonococcal urethritis; Rare infections such as Tularaemia and bubonic plague. The following undesirable effects have been reported for demecycline: loss of appetite, nausea, vomiting, diarrhea, inflammation of the tongue, difficulty in swallowing, intestinal inflammation, and inflammatory lesions, rashes, redness of the skin, pigmentation, sensitivity to light, acute kidney failure and others.