The benefits of RFID technology in the healthcare sector are widely acknowledged. Nevertheless, the adoption of RFID as a means for pure item identification prevents adequate support to most knowledge-intensive medical tasks. Here an innovative Decision Support System for healthcare applications is presented, based on a semantic enhancement of RFID standard protocols. Semantically annotated descriptions of both medications and patient's case history are stored in RFID tags and used to help doctors in providing the correct therapy. The proposed system allows to discover possible incompatibilities in a therapy suggesting alternative treatments.