Pharmakon (Greek) = Medicinal Substances

Vigilia (Latin) = To keep watch

WHO Definition of Pharmacovigilance

The science & activities relating to the detection, assessment, understanding & prevention of adverse effects or any other drug related problems

Aim of Pharmacovigilance

To improve patient care and safety in relation to the use of medicines, and all medical and paramedical interventions

To improve public health and safety in relation to the use of medicines.

Why Pharmacovigilance is needed?

The information collected during the pre-marketing phase of a medical drug is inevitably incomplete with regard to possible adverse reactions:


  • tests in animals are insufficiently predictive of human safety,
  • in clinical trials patients are selected and limited in number, the conditions of use differ from those in clinical practice and the duration of trials is limited,
  • information about rare but serious adverse reactions, chronic toxicity, use in special groups (such as children, the elderly or pregnant women) or drug interactions is often incomplete or not available

Where is Pharmacovigilance used?

Pharmacovigilance is needed in every country, because there are differences between countries in the occurrence of adverse drug reactions and other drug-related problems. This may be because of differences in:


  • drug production
  • distribution and use (e.g. indications, dose, availability)
  • genetics, diet, traditions of the people
  • pharmaceutical quality and composition (excipients) of locally produced pharmaceutical products
  • the use of non-orthodox drugs (e.g. herbal remedies) which may pose special toxicological problems, when used alone or in combination with other drugs.