29ADVERSE DRUG REACTIONS: AN OVERVIEWAdverse drug reactions (ADR’s) are defined the effects created by drugs producing unintended or noxious response. Also, an ADR is a response to a medicine which is noxious and unintended, and which occurs at doses normally used in man for the prophylaxis, diagnosis, or therapy of disease or for the modification of a physiological function. The evaluation of ADRs adapts various factors that can predispose patients to adverse reactions. The types of adverse reaction can be studies in two main headings, i.e., more common ADRs including type A and B reactions; and less common ADRs which include type C, D and E reactions. The present review article explains about the various types and mechanisms of adverse reactions.ankurrohilla1984@gmail.comResearch322013Adverse drug reactionsAnkur Rohilla,Singhraj YadavDepartment of Pharmaceutical Sciences, Shri GopichandGroup of Institutions, Baghpat-250609, UP, India,Department of Pharmaceutical Sciences, Shri GopichandGroup of Institutions, Baghpat-250609, UP, India