Introduction
Pharmacovigilance is the detection, assessment, understanding and prevention of adverse effects of medicines after they are marketed. Its oldest and most important tool is spontaneous reporting, known in the UK and widely as the Yellow Card scheme (introduced in 1964 after thalidomide).
ADR: definition
A response to a medicine that is noxious and unintended, at normal doses or through off-label use, overdose, misuse, abuse or error (EU definition).
The spontaneous reporting system
- Doctors, pharmacists, nurses and, since 2012 in the EU, patients report suspected ADRs to the national agency (in Bulgaria the Bulgarian Drug Agency, online or by form).
- Reports go into the national database, the EU EudraVigilance system and the WHO Uppsala Monitoring Centre (VigiBase).
- Regulators look for signals: new reactions or more frequent known ones. They can update the SmPC, restrict use or withdraw the drug.
What to report
- Any suspected ADR to a drug with the black triangle ▼ (additional monitoring).
- Serious reactions to any drug, and unexpected ones (not in the SmPC, or more frequent or severe than described).
- Reactions in children, the elderly, pregnancy, from vaccines, herbal medicines and medication errors.
- Report even if not sure the drug caused it; certainty is not required.
What a report contains
An identifiable patient, a reporter, the suspected drug(s) and the reaction: the minimum for a valid report. Add dates, doses, other drugs, outcome, dechallenge and rechallenge.