Abstract: The invention is related to an iontophoretic method for the delivery of a compound of the formula wherein R is defined herein, and pharmaceutically acceptable salts and prodrugs thereof; and, wherein the method comprises: (a) applying a transdermal device to the skin of a living body, wherein the transdermal device has a reservoir containing the compound of formula I or a composition thereof and optionally a pharmaceutically acceptable electrolyte; (b) causing current to flow through the skin so as to iontophoretically deliver the compound of formula 1. The invention is further related to iontophoretic systems and to kits containing the iontophoretic system combined with one or more cartridges containing a compound of formula I, and to cartridges containing a compound of formula I.