Dexamethasone and Chloramphenicol belong to the class of medicines known as corticosteroids and antibiotics, respectively. 

Dexamethasone is used to treat skin diseases, blood disorders, arthritis, or immune system disorders. It belongs to the class of medications known as corticosteroids. It works by lessening the response of the immune system to numerous diseases to lessen the symptoms including allergic-type reactions and swelling. 

On the other hand, Chloramphenicol is an antibiotic that works by stopping bacterial growth.