A medicament delivery device is presented for the administration of one or more drug agents, wherein the device comprises a retainer for holding a medicament cartridge. The retainer is moveable between an open and closed position. A position sensor for generating a position output is indicative of whether the retainer is in the open or closed position. Further, a cartridge sensor generates a cartridge output indicative of whether the retainer is holding a medicament cartridge. A controller controls a predetermined operation of the device in dependence on the output of the position sensor and on the output of the cartridge sensor.
