Tequin antibiotic molecule. Computer model of a molecule of tequin, a broad spectrum antibiotic. The molecule's surface is colour-coded based on the underlying atoms: carbon (light blue), hydrogen (white), oxygen (red), nitrogen (dark blue) and fluorine (green). Tequin kills bacteria by preventing them from replicating their DNA (deoxyribonucleic acid). It is used to treat infections of the lungs, sinuses, urinary tract and the sexually transmitted disease gonorrhea. Tequin should not be taken by diabetics because it can cause hyperglycaemia (high blood sugar) or hypoglycaemia (low blood sugar).