An intrathecal drug delivery system (100) configured to improve dispersion of medicament with cerebral spinal fluid in a subarachnoid space of a patient. The intrathecal drug delivery system including an implantable medical pump (102) and a catheter (300, 400, 500, 600, 700, 800) having a wall (304, 404, 508, 608, 708, 808) defining a lumen extending between a proximal end in fluid communication with the implantable pump and structure defining a medicament exit (308, 408, 506, 606, 706, 806) positionable within the subarachnoid space of the patient, the wall further defining at least one feature (310, 410A, 410B, 410C, 510, 670, 710, 810) configured to generate vortices within the cerebrospinal fluid for the purpose of improving intrathecal drug dispersion.
