A drug delivery device includes a blunt cannula and a reservoir. The blunt cannula has a cylindrical wall that defines an axial passage between a first end and a second end of the blunt cannula. The wall has at least a first tapered region at the first end to define an opening in fluid communication with the axial passage and adapted at the first end to resist interruption of fluid flow through the axial passage and out of the first end of the blunt cannula. The reservoir is connected to the second end of the blunt cannula.