As defined by the World Health Organization (WHO), an adverse drug event is an event that is “noxious and unintended and occurs at doses used in man for prophylaxis, diagnosis, therapy, or modification of physiologic functions.” ADE’s in a hospital may be detected not only by their reporting, but also by other events which may suggest that a patient may have had an ADE. Such events include discontinuation of the medication, decrease in dosage, ordering of certain laboratory tests, specific test abnormalities, and low white blood cell counts. A questionnaire given the patient, called a Naranjo algorithm, can also be used.
An unpleasant or unwanted effect caused by medication.