what is an adverse reaction to a drug
An adverse drug reaction is a âresponse to a drug which is noxious and unintended and which occurs at doses normally used in man for prophylaxis, diagnosis, or therapy of disease or for the modification of physiologic function.â Note that there is a causal link between a drug and an adverse drug reaction.nder this definition, the term ADE includes harm caused by the drug (adverse drug reactions and overdoses) and harm from the use of the drug (including dose reductions and discontinuations of drug therapy).â 1 Adverse Drug Events may results from medication errors but most do not.