A discharger for discharging a predetermined amount of fluid includes a housing defining a longitudinal axis and having a proximal end and a distal end, a discharge section having a discharge passage for the fluid extending between an inlet opening and an outlet opening of the discharge section, a carriage cooperating with the proximal end region of the housing such that the carriage is moveable relative to the housing along the longitudinal axis, and securing devices engageable with each other such that they define a locking position in which the carriage is prevented from being moved along the longitudinal axis, the securing device being disengageable to define a starting position for the carriage by simultaneously applying a first actuating force to the housing and a second actuating force to the carriage, the first actuating force being brought about by a radial compression of the housing.