Abstract: An implantable arterial catheter, especially a multidose catheter, comprises a multidose injection receptacle that includes a shell which bounds a chamber having an open end and has a fastening flange. A pierceable diaphragm spans the open end of the chamber to sealingly separate the chamber from the exterior of the shell. An elongated catheter tube has one end connected to the multidose injection receptacle and communicating with its chamber, and another end portion remote from the multidose injection receptacle. A safety valve is secured to the other end portion of the catheter tube and includes a conical tip component disposed at the other end portion of the catheter tube and having a flow orifice at the apex thereof, and a protective cap component surrounding the conical tip component and the other end portion of the catheter tube, secured to the catheter tube, and having a free end provided with an additional flow orifice.