An improved injection or blood removal device for intravenous access has a port with a septum (5) at the exterior end of an intravenous catheter (3) a coupling element having an adhesive surface (15) for securing attachment onto the skin an injection or blood sampling unit a connecting cannula (20) piercing the septum of the port and means to secure functional assembly. Attachment of the device to the skin covering or close to the intravenous puncture site and without long communicating tubes allows ambulant injection of drugs or measuring of concentration time profiles of exogenous and endogenous analytes to improve treatment modalities on an individualized basis.
