A drug infusion device (11), including a casing (13), a ferrule (15) having coupling means (20) for receiving a syringe (25) equipped with a sliding piston (63), and a pusher (17), which is axially movable to make said piston (63) slide in the syringe, said pusher being associated with a sliding rod (19) that is partially received within the casing (13) and projects therefrom through an opening (21) provided in the ferrule (15), said casing (13) housing the driving members causing the axial sliding of the sliding rod (19), said driving members including an electric motor (35) electronically controlled by a programmable electronic controller and programmed to cause the infusion of the drug contained in the syringe fit onto the device, wherein said controller is also programmed to cause the suction of a drug into the syringe fit onto the device.
