An antibiotic derived from a soil organism, Streptomyces venezuelae. It is also prepared synthetically. A potent broad-spectrum antibiotic, chloramphenicol may, however, cause serious side-effects such as aplastic ANAEMIA, peripheral NEURITIS, optic neuritis and, in neonates, abdominal distension and circulatory collapse. The drug should therefore be reserved for the treatment of life-threatening infections such as Haemophilus influenzae, SEPTICAEMIA or MENINGITIS, typhoid fever (see ENTERIC FEVER) and TYPHUS, when the causative organism proves resistant to other drugs. However, because it is inexpensive, it is used widely in developing countries. This antibiotic is available as drops for use in eye and ear infection, where safety is not a problem.