2. Adverse Event (AE) versus Adverse Reaction (adverse drug reaction ADR) – the distinction



1. Adverse Event (AE) versus Adverse Reaction (adverse drug reaction ADR) – the distinction


The assessment of a signal in Pharmacovigilance and its classification as a safety risk or not associated with the use of a medicine determines the course of (regulatory) action to be taken. In this respect it is helpful, if not a prerequisite, to be aware of the terminology used to distinguish between an Adverse Event (AE) and an Adverse Reaction (also called Adverse Drug Reaction (ADR)). The following section on this distinction is largely based on the EMA Guideline on good pharmacovigilance practices (GVP) Annex I - Definitions (Rev 4)[1].


The terminology used in the EUPATI texts follows Regulation (EU) No 536/2014 where applicable. This regulation entered into force in 2014 but is only applicable six months after the publication of the notice referred to in Article 82(3) (see Article 99 of Regulation (EU) No 536/2014). The timing of the application of Regulation (EU) No 536/2014 depends on confirmation of full functionality of the EU clinical trial portal and database through an independent audit, which is still pending.