An arrangement for a drug delivery device (1) comprising: - a housing (2) - a dose member (22) adapted to rotate in a direction of adjustment of the dose vs. lacarcasa (2) to set a dose of a drug (5) and rotated in a direction of administration dosiscon regarding housing (2) to manage the set dose, the dose member (22) a guide element (46), comprising - a guide rail (42) configured to mechanically cooperate with the guide element (46), the rail comprising guide (42) a first section (43A) and a second section (43B), which are all connected by a connecting region (55), wherein the first section (43A) defines unaposición angular start (54) the guide element (46), and the second section (43B) defines a positionof axial stop (56) for the guide element (46), and - a spring member (26), characterized in that when the dose member ( 22) is rotated in the direction of titration, the guide element (46) is SCROLLING It aza angularly from the position of angular start (54) to the connection region (55), elmiembro spring (26) deviates torsionally tending spring member target (26) angularly adesplazar the guide element (46) towards the angular position of start (54) and that, when elelemento guide (46) has passed the connection region (55), the guide element (46) enters the segundasección (43B) and moves axially in a proximal direction with respect to the housing (2) to laposición axial stop (56) and in the position of axial arrest reducing desviacióntorsional is prevented by the mechanical cooperation of the guide element (46) and the second section (43B).Una disposición para un dispositivo de administración de fármaco (1), que comprende: - una carcasa (2) - un miembro de dosis (22) adaptado para girar en una dirección de ajuste de la dosis con respecto a lacarcasa (2), para ajustar una dosis de un fármaco (5) y girar en una dirección de administración de la dosiscon respecto a la carcasa (2) para administrar la dosis establecida, comprendiendo el miembro de dosis (22)un elemento
