Tetracyn is part of the Tetracycline Antibiotics class and treats Pneumonia, Typhoid, Bacterial Infection and other conditions. Tetracycline antibiotics are used to treat acne and rosacea, and bacterial infections including pneumonia, lower respiratory infections, upper respiratory infections, urinary tract infections, eye infections, malaria, and typhoid. They work by killing the bacteria that is causing the infection. Tetracyn is only available as a brand name drug.