What happens after I report an adverse drug effect?

All reports are collected by the pharmacovigilance authorities in your country (public health authorities). They also receive reports from healthcare professionals. It is crucial that you fill in all the fields on the reporting form - all the information is important.

In some cases the pharmacovigilance authorities will need to learn more about what happened, and they can only do so if you accept to provide your contact details with the report. You can also provide the name of your doctor who will then contact you, if needed. However this is not mandatory, if you prefer to remain anonymous, you can do so.

Serious side effects will be processed and analysed in priority. The analysis will be conducted at the level of your country, and your report will also be sent to a European database where reports from all EU countries are stored and analysed.

All information collected at the national level is then sent to a European depository of all reports across the EU, called EudraVigilance. This applies for serious adverse reactions, and in the future will apply to all side effects, serious or minor.

EudraVigilance data for centrally authorised medicines (all medicines that are evaluated directly by the European Medicines Agency in London, i.e. all orphan drugs) are analysed on a regular basis, with a two-week or four-week frequency.

Experts will discuss the following points:


  1. Is the report about something which is already known about the drug? Or is it new?
  2. Is the report isolated? Or have other patients/healthcare professionals reported similar events?
  3. How frequent is this? How many patients are concerned, out of the total number of patients treated?
  4. Is the adverse event likely to be caused by the drug, or not?
  5. If it is confirmed that this is a new effect caused by the drug, which measures should be taken?
    1. To Inform patients and healthcare professionals (e.g. change the package leaflet)
    2. To reduce the risk of occurrence (e.g. reduce the dose in patients at risk)
    3. To inspect the drug manufacturing sites, if needed
    4. Any monitoring or surveillance study to further document the effect…

All these steps are conducted in a timely manner, but there may be some delay between the time patients report and when authorities make adequate decisions. These discussions can take place in your country, and at the European level, so that information, views and decisions can be shared with all Member States.

  • Case reports of suspected adverse reactions alone are rarely sufficient to confirm that a certain effect in a patient has been caused by a specific medicine.
  • The fact that a suspected adverse reaction has been reported does not necessarily mean that the medicine has caused the observed effect as this could have also been caused by the disease being treated, a new disease the patient developed, or by another medicine that the patient is taking. Case reports need therefore to be assessed by an expert.
  • A single case report should be seen as a piece of a jigsaw puzzle, where further data are usually needed to complete the picture.
  • The number of case reports for a particular medicine does not only depend on the real frequency of the adverse reaction but also on the extent and conditions of use of the medicine, the nature of the reaction as well as public awareness. Comparing numbers of case reports between medicines may give a misleading picture of their safety profiles.

Guide on the interpretation of spontaneous case reports of suspected adverse reactions to medicines


A document published by the European Medicines Agency explains key considerations:

what happens to a patient's spontaneous side effect report. It is transmitted to the authorities in the Member State where the report is made, and also to European authorities, so that all experts from across Europe are informed.

What happens to a patient's spontaneous side effect report? It is transmitted to the authorities in the Member State where the report is made, and also to European authorities, so that all the experts across Europe are informed.

In other words, a patient’s report goes first to the national experts in charge of pharmacovigilance. It is checked, verified, completed, analysed and then sent to the European system for further analysis, and pooled with equivalent reports from across the EU and beyond.

Page created: 08/11/2012
Page last updated: 07/11/2014
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