Paracetamol. Computer model of a molecule of the drug paracetamol. It is also known as acetaminophen, and is sold under a wide variety of brand names. It is an analgesic and antipyretic drug, used to treat pain and fevers. The molecule's chemical formula is C8.H9.N.O2. Atoms (spheres) are colour-coded: carbon (grey), hydrogen (light blue), nitrogen (dark blue), oxygen (red).