Pharmacovigilance Systems and Reporting
Pharmacovigilance systems and reporting comprise the organised structures and processes used to collect, record, evaluate, and act on information about adverse effects of medicines once they are in use. Because pre-marketing clinical trials enrol limited numbers of patients for limited periods, many risks become visible only after a product reaches the wider population; reporting systems are the infrastructure through which those risks are captured and turned into safety knowledge.
Definition
Pharmacovigilance systems and reporting refer to the science and activities relating to the detection, assessment, understanding, and prevention of adverse effects of medicines, together with the reporting structures, databases, and standards that support them.
Scope
This area orients the reader to how drug-safety information is gathered and handled. It groups the principal modes of data capture (spontaneous and active surveillance), the analytic step of signal detection, and the international databases and terminologies that make safety data comparable across countries. It is a reference overview of methods and infrastructure, not clinical guidance on managing individual reactions.
Sub-topics
Core questions
- How are suspected adverse drug reactions captured after a medicine is marketed?
- What distinguishes passive (spontaneous) reporting from active surveillance?
- How are potential safety signals identified and assessed from accumulated reports?
- What international databases and terminologies make safety data comparable across countries?
Key concepts
- Adverse drug reaction (ADR)
- Spontaneous (passive) reporting
- Active surveillance
- Under-reporting
- Signal detection
- Causality assessment
- Individual case safety report (ICSR)
- Post-marketing surveillance
Mechanisms
Most pharmacovigilance begins with an individual case safety report describing a suspected reaction to a medicine. Spontaneous reporting depends on clinicians, pharmacists, manufacturers, and patients voluntarily submitting such reports to national centres and regulators; active surveillance instead deliberately seeks out events in defined populations. Reports are coded with standard terminologies and pooled into databases, where statistical and clinical review looks for patterns that may indicate a previously unrecognised hazard. Confirmed signals can lead to label changes, restrictions, or withdrawal, closing the loop between observation and action (Edwards & Aronson, 2000; Stricker & Psaty, 2004; Härmark & van Grootheest, 2008).
Clinical relevance
Pharmacovigilance systems are the means by which the medical community learns about harms that were not apparent at the time a medicine was approved, and understanding them supports critical reading of drug-safety information. This entry describes how safety evidence is generated and organised; it is not a basis for individual diagnostic or treatment decisions.
Epidemiology
Adverse drug reactions are a substantial source of morbidity: meta-analytic estimates have placed serious ADRs among hospitalised patients in the United States in the millions per year, and prospective hospital studies have attributed a meaningful share of admissions to drug-related harm (Lazarou et al., 1998). These figures motivate systematic surveillance rather than reliance on clinical trials alone.
History
Modern pharmacovigilance is usually traced to the thalidomide tragedy of the early 1960s, which exposed the inadequacy of relying on pre-marketing data and prompted the establishment of national reporting schemes and, in 1968, the World Health Organization's international drug-monitoring programme. Over subsequent decades the field expanded from passive collection toward active surveillance, quantitative signal detection, and harmonised international standards (WHO, 2002; Härmark & van Grootheest, 2008).
Key figures
- I. Ralph Edwards
- Jeffrey K. Aronson
- Bruno Stricker
- Linda Härmark
Related topics
Seminal works
- edwards-aronson-2000
- harmark-2008
- lazarou-1998
Frequently asked questions
- Why is pharmacovigilance needed if medicines are tested in clinical trials first?
- Trials enrol a limited number of patients for a limited time and often exclude special populations, so rare, delayed, or population-specific reactions may appear only once a medicine is used widely. Pharmacovigilance systems capture those post-marketing experiences.
- What is an adverse drug reaction?
- It is a response to a medicine that is noxious and unintended and that occurs at doses normally used in humans; distinguishing it from coincidental events is part of the work of causality assessment within pharmacovigilance.