Vancomycin has been utilized as an antimicrobial therapeutic agent for serious gram positive infections for more than half a century.The pharmacokinetics of vancomycin has been well studied, and in general there are few side effects from this medication. The most common side effect that occurs with receipt of vancomycin is red man syndrome (RMS), which is also known as red neck, or red person syndrome.1 RMS encompasses a spectrum that ranges from a mild reaction such as flushing, urticarial rash, pruritis, to a severe reaction that includes generalized erythema,intense pruritis, and even hypotension. RMS has been estimated to occur in 5- 50% of hospitalized patients who receive this drug.