The adoption of emerging semantic Web technologies will lead computer-based medical systems to a new dimension. These systems will benefit from next generation web knowledge representation languages and reasoning facilities. This paper describes such an application which aims to provide several services related to drug consumption. The originality of this approach relies on its general-public orientation. We already have a development experience in this field with XIMSA (interactive multimedia system for auto-medication). XIMSA is a logical extension of this system which incorporates some new features based on the use of a formal Web ontology.