Chloramphenicol : another antimicrobial agents is recommended only for treatment of life – threathening infection for example, bacterial meningitis or rickettsial infection. Dexamethasone : Very potent and highly selective glucocorticoid. Long acting. Causes marked, pituitary-adrenal suppression, but fluid retention and hypertension are not a problem. It meets any emergency with intensified potency and strikingly rapid corticosteroid action, thus ensuring speedy reversal of the situation in the patients favour.