RESUMO
The safety profile of a drug is not a static concept. It progresses and can change on the basis of scientific data gathered before and after it is marketed. Therefore, it is now considered fundamental that all countries have the capacity to continuously monitor the safety of medicines authorized for sale. Based on the resulting and appropriate data, this allows them to alter the previously authorized conditions for use of a given drug as a public health safeguard. This paper describes how a pharmacovigilance system is being developed in Portugal in the 1990s. The system is being implemented based on our national characteristics and positions within the European Union. The article includes some results from the initial implementation of these methods. Many similarities allow one to extrapolate some of the procedures from one country to another. When we began we borrowed and adapted extensively from experiences already tested by others.