Chlorodex is a combination of two medicines: Chloramphenicol and Dexamethasone. Chloramphenicol is an antibiotic which stops bacterial growth in the eye/ear by preventing the synthesis of essential proteins required by the bacteria to carry out vital functions. Dexamethasone is a steroid. It blocks the production of certain chemical messengers (prostaglandins) that make the eye/ear red, swollen and itchy.