A socio-technical approach was used to study the qualitative effects of deploying a medication computerized physician order entry system (CPOE with no decision support) at two internal medical wards in a hospital in Denmark. Our results show spatial and temporal transformations of core acts and relations in medication work, i.e. of the intended use of the system inscribed in hardware and software, in the relations of care between doctors and patients, of collaboration between doctors and nurses, and prospectively of the patients' trajectories when readmitted to hospital or another health care institution, reusing data from the system. This study throws light on problems of continuity of patient care paths, patient-related and IT-system-related error handling and time spent on core activities--when ubiquitous IT is used locally in a real physical setting with specific traditions of performing or 'doing medication'. The paper argues for the project organization to support the local collaboration and renegotiation of time and place of enacting medication with CPOE, as well as set up feedback for maturation of the software for future clinical use.