Medicament infusion systems and fitting therefor

A drug delivery system has a fluid store that has a first tubing having an outlet fitted with a connector of a given configuration that prevents the connector from being coupled to a conventional counterpart connector. The system further has a tube retaining device that has a catheter extending out of one of its ends and an inlet connector at its other end that has a configuration complementary to the configuration of the outlet connector of the first tubing, so that the first tubing may be matingly connected to the tube retaining device to establish a through fluid path from the first tubing to the catheter. A one-way valve may be provided to the tubing to prevent fluid from flowing backwards into the tubing. A fitting that enables the inventive system to be used with conventional IV stores and syringes is also disclosed.