A syringe comprising a barrel and a plunger rod having a proximal portion and a distal portion is provided. The distal portion includes a stopper slidably positioned in fluid-tight engagement with the inside surface of the barrel. The structure is provided for holding the proximal portion and the distal portion together during normal use of the syringe and breakable upon application of an additional force applied to the proximal portion. Structure is also provided for preventing the proximal portion from applying distally directed force to the distal portion after the breakable connection is broken.