Recent research work on feasible solutions for electronic data exchanges in the european pharmacovigilance domain (EPhV) has facilitated a better understanding on strategic and operational factors inherent to such a class of transnational vigilance information systems. Most of the material presented here has resulted from the CARE - Pharmacovigilance Pilot project of the ENS-Telematics Programme, and from other subsequent research activities like the IDA feasibility study and the TEDIS-EuroSCape project. Attention has been paid to design principles and features of a communication scheme that must be used to support cooperative problem solving within a network of loosely connected autonomous and hetereogeneous agents. Experience confirmed two key-success factors : a) the users leading role, and b) the Pilot approach putting the focus on standardized electronic data interchange for communicating existing different local systems.