A drug administering device comprises: a casing front portion in which a cavity is formed and which comprises front connecting means, a drug container received in said cavity, a casing rear portion comprising a piston rod which is displaceable into said cavity, and rear connecting means for releasably connecting to said front connecting means, wherein said casing front portion comprises at least two members which, in locking engagement with each other, delimit a front portion of said cavity and a rear portion having a cross section which is narrower than that of the front portion and too narrow for the drug container to pass.一種藥物施配裝置包括:一殼體前部,一腔體形成在殼體前部中並且殼體前部包括一前連接構件,一藥物容器,收納在腔體中,一殼體後部,包括一活塞桿以及一後連接構件,活塞桿能够移動到腔體中,並且後連接構件用於可脫開地連接到前連接構件,其中,殼體前部包括至少兩個部件,此至少兩個部件彼此鎖定嚙合,此至少兩個部件劃分腔體的前部和後部,後部的截面相比較於前部的截面更窄並且窄到藥物容器無法通過。2‧‧‧殼體前部10‧‧‧蓋子12‧‧‧管狀部件15‧‧‧凸螺紋16‧‧‧孔24‧‧‧保持部件36‧‧‧藥物容器37‧‧‧腔體38‧‧‧腔體前部39‧‧‧腔體後部40‧‧‧活塞
