According to the World Health Organization (WHO) pharmacovigilance (PV) is defined as the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other drug-related problem.

Regarding marketed medicinal products, a well-accepted definition of an adverse drug reaction in the post-marketing setting is as follows:

A 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 modification of physiological function (WHO, 1972).



In 1986, CIOMS set up its first Working Group on pharmacovigilance, a Working Group on International Reporting of Adverse Drug Reactions to explore means of coordinating and standardizing international adverse drug reporting by pharmaceutical manufacturers to regulatory authorities. Its agenda was limited to post-marketing reporting of adverse drug reactions occurring in one country and which the pharmaceutical industry should report to regulatory authorities in other countries where the drug is also marketed.

In 1977, a CIOMS Conference on “Trends and Prospects in Drug Research and Development” recommended that, by offering an independent forum, CIOMS should facilitate discussion of policy matters between the research-based pharmaceutical companies and national regulatory authorities, and, when indicated convene groups of experts to make recommendations on specific issues.



Since the 1980s CIOMS has launched a series of Working Groups to address hot topics of pharmacovigilance. All the groups have produced valuable results in the form of published Working Group reports (see below).

The CIOMS Cumulative Pharmacovigilance Glossary compiles the definitions from past reports. As the science and practice of pharmacovigilance have evolved over the past decades, so too have the related definitions. CIOMS intends to maintain this glossary as a living document and welcomes all feedback. Thank you for emailing recommendations to

CIOMS Working Group reports on pharmacovigilance topics:

  • Drug-induced liver injury (DILI), 2020
  • CIOMS Guide to Vaccine Safety Communication, 2017
  • CIOMS Guide to Active Vaccine Safety Surveillance, 2016
  • … (and many more)