Current postmarketing surveillance methods largely rely on spontaneous reports which suffer from serious underreporting, latency, and inconsistent reporting. Thus they are not ideal for rapidly identifying rare adverse drug reactions (ADRs). We propose an active, multi-agent computer software system, where each agent is empowered with teamwork capabilities such as anticipating information needs, identifying relevant ADR information, and continuously monitoring and proactively sharing such information in a collaborative fashion with other agents. The main purpose of this system is to help regulatory authorities (e.g., FDA in the U.S.) find previously unrecognized ADRs as early as possible. Another objective is to promote increased filing of on-line ADR reports thereby, addressing the severe underreporting problem with the current system. The proposed system has the potential to significantly accelerate the process of ADR discovery and response by utilizing electronic patient data distributed across many different sources and locations more effectively. Our preliminary system design is presented and some issues related to it are discussed.