Risks associated with modern drugs expand and develop beyond our existing control and perception mechanisms. New medicines have the ability to transform side effects from the traditional individual physical level to a societal level in the form of economic, political and ethical consequences. Existing assessment methods cannot capture or cope with the side effects we will experience with tomorrow's drugs. We interpret this as a sign of the need for on-going methodological developments within Medical Technology Assessment (MTA) to capture and include the as yet 'unknown' and 'unforeseen' economic, political and ethical risks of modern drugs. In this paper, we argue that a prospective inter-disciplinary approach should be applied to MTA as a form of 'early warning system', using the Delphi method combined with prospective scenarios to keep up with the changing characteristics of new drugs.