The United States Food and Drug Administration (FDA) has approved Ionsys (fentanyl iontophoretic transdermal system), the first needle-free, patient-activated analgesic system. Ionsys is intended for the short-term management of acute postoperative pain in adult patients requiring opioid analgesia during hospitalization. Patients should be titrated to an acceptable level of analgesia prior to initiating treatment with Ionsys. 

Ionsys is made up of a compact electronic controller and two hydrogel reservoirs, one of which contains fentanyl hydrochloride in a gel formulation for needle free, on-demand delivery. The upper part of the product is white and usually contains the identifier Ionsys.

Ionsys should be strictly restricted to hospital use only. Due to the well-known potential of abuse of fentanyl physicians should evaluate patients for a history of drug abuse. The patient should themselves activate Ionsys. Before any surgery, the physician should ensure that the patient has been properly informed on how to use Ionsys post-operatively. Ionsys delivers 40 micrograms per on-demand dose up to a maximum of 240 micrograms per hour but not more than a maximum of 80 doses within a 24-hour period. The patient in response to pain should only activate the system. Ionsys will operate for 24 hours following completion of the first dose or for 80 doses; whichever comes first, and then becomes inoperative. If the patient attempts to initiate a dose after 80 doses or 24 hours from the first dose, the system will not respond. The maximum treatment duration is 72 hours, although the majority of patients should only need one system. Patients should not wear more than one system at a time.