Described is a cartridge (4) comprising a case adapted to detachably engage an autoinjector (1), an ampoule (4.1) containing a medicament, and a needle magazine (5) containing a plurality of double-tipped needle assemblies (5.1). An autoinjector (1) comprises the cartridge (4), a housing (2) adapted to detachably engage the cartridge (4) and a user interface adapted to provide visual, audible or tactile feedback.