Table 1.

Safety reporting terminology for investigational new drugs (INDs)46

Reporting term	Definition
Adverse event	Any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related
Adverse reaction	Any adverse event caused by a drug
Life-threatening adverse event or life-threatening suspected adverse reaction	An adverse event or suspected adverse reaction is considered “life-threatening” if, in the view of either the investigator or sponsor, its occurrence places the patient or subject at immediate risk of death
Serious adverse event or serious suspected adverse reaction	An adverse event or suspected adverse reaction is considered “serious” if, in the view of either the investigator or sponsor, it results in any of the following outcomes: death, a life-threatening adverse event, inpatient hospitalization or prolongation of existing hospitalization, a persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions, or a congenital anomaly/birth defect
Suspected adverse reaction	Any adverse event for which there is a reasonable possibility that the drug caused the adverse event
Unexpected adverse event or unexpected suspected adverse reaction	An adverse event or suspected adverse reaction is considered “unexpected” if it is not listed in the investigator brochure or is not listed at the specificity or severity that has been observed; or, if an investigator brochure is not required or available, is not consistent with the risk information described in the general investigational plan or elsewhere in the current application, as amended

Notes: The US Code of Federal Regulations defines the terms used for identifying unfavorable, negative, or harmful medical occurrences in clinical trials of INDs and bioavailability and bioequivalence studies. An “adverse event” is an untoward medical occurrence in any clinical trial subject (eg, receiving study drug or placebo) regardless of causality, while an “adverse reaction” is an untoward medical occurrence that is caused by a drug. All definitions are from: US Food and Drug Administration. Investigational new drug safety reporting requirements for human drug and biological products and safety reporting requirements for bioavailability and bioequivalence studies in humans. Federal Register. 21 CFR Parts 312 and 320. 2010;75(188):59935–59963. Available from: http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2010_register&docid=fr29se10-3.pdf. Accessed September 2, 2011.