A device (20) is disclosed for dispensing a fluid supplied from an external fluid source. The device comprises a transducer (32) adapted to receive a fluid from the fluid source, and a collapsible linkage and trip link (502) coupling the transducer and the fluid source. The linkage has a collapsible joint inhibiting discharge of the fluid source when in a locked orientation. The device (20) further comprises a moveable member coupled to the linkage such that inhalation forces on the device cause the linkage to collapse thereby discharging the fluid from the fluid source. The device may further include a dose counter coupled to the fluid source for registering the amount of doses administered from the fluid source.
