A therapeutic agent injection device including an injection device for delivering a therapeutic agent to a patient having a body, the body having a patient face and a port face opposite the patient face, the port face having an introducer port including an introducer channel and an injection port including an injection channel, the introducer channel being in fluid communication with the injection channel through a cross channel, the injection channel defining an injection axis; a delivery tube for subcutaneous delivery of the therapeutic agent to the patient, the delivery tube projecting from and being generally perpendicular to the patient face, the delivery tube defining an introducer axis and being in fluid communication with the injection port; and a patch, the patch being attached to the patient face and being operable to adhesively attach to the patient; wherein the injection axis is parallel to the introducer axis.