FIELD: medicine.SUBSTANCE: invention refers to medical equipment, namely, refers to a syringe device, and specific versions refers to a mechanism to prevent the syringe reuse. The syringe comprises a cylinder having a cylindrical side wall, an elongated hollow piston rod, a trim at a distal end of the piston rod, and a blocking element. The cylinder has an inner surface forming a chamber for retaining a fluid, an open proximal end and a distal end with a distal wall which provides a passageway for fluid into the chamber. The rod has a proximal end, an open distal end, an inner surface and a distal edge projecting at a distal end. The trim comprises a sealing element with a peripheral surface forming a seal with the inner surface of the cylinder, and a projection extending from the sealing member in the proximal direction and forming a longitudinal recess having a distal portion and accommodating on this distal portion a number of surfaces forming an inclination diverging outwards in the distal direction and a number of supports on the proximal end. The blocking element has a proximal portion having a proximal edge and a distal portion provided with a tooth facing the outside. The blocking element is positioned in the longitudinal recess so that the tooth interacts with the inner surface of the piston rod, and the proximal edge interacts with the projection on the proximal end of the longitudinal groove. The number of the surfaces forming the inclination and the number of supports on the proximal end of the longitudinal recesses interacts so that the distal portion of the blocking member moves along the number of the surfaces forming the inclination with shifting the distal portion of the blocking member to the outside towards the inside of the rod while sliding in the distal direction of the rod and the blocking element. When slides together with the trim inside the chamber at first in the proximal direction and then towards its distal end, the rod makes the tooth p
