A transdermal system for the delivery of an anesthetic or other active therapeutic agent directly to a selected site of injured skin tissue by iontophoresis is disclosed, which utilizes a transdermal skin-worn patch including a donor electrode chamber containing a donor electrode and an amount of an active agent in a form suitable for transdermal delivery in electrical communication with the donor electrode and a return electrode. The patch also contains a source of electric current connected in a circuit with the donor and return electrode, a current regulating device is optionally provided in the circuit for controlling the electrical output of the patch and at least the donor electrode chamber includes a provision for absorbing a quantity of fluid associated with weepage from adjacent injured skin tissue.