Adverse event

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Adverse event" – news · newspapers · books · scholar · JSTOR (May 2013) (Learn how and when to remove this message)

In pharmaceuticals, an adverse event (AE) is any unexpected or harmful medical occurrence that happens to a patient during medical treatment or a clinical trial. Unlike direct side effects, an adverse event does not necessarily mean the medication directly caused the problem. These events can include any unfavorable symptoms, signs, or medical conditions that appear during medical treatment, regardless of whether they are definitively linked to the specific medication being studied.^[1]

AEs in patients participating in clinical trials must be reported to the study sponsor and if required could be reported to the local ethics committee. Adverse events categorized as "serious" (results in death, illness requiring hospitalization, events deemed life-threatening, results in persistent or significant incapacity, a congenital anomaly or medically important condition) must be reported to the regulatory authorities immediately, whereas non-serious adverse events are merely documented in the annual summary sent to the regulatory authority.

The sponsor collects AE reports from the local researchers, and notifies all participating sites of the AEs at the other sites, as well as both the local investigators' and the sponsors' judgment of the seriousness of the AEs. This process allows the sponsor and all the local investigators access to a set of data that might suggest potential problems with the study treatment while the study is still ongoing.