Fentanyl by iontophoresis: new drug. Patient-controlled postoperative analgesia: continue to use intravenous morphine.

(1) A transdermal system for fentanyl, an opiate analgesic, will soon be marketed in France for patient-controlled relief of acute postoperative pain. Pushing a button delivers a dose of fentanyl (contained in a reservoir) into the general circulation by transdermal route, by means of iontophoresis, a needle-free technique; (2) The European Medicines Agency only took into account one comparative trial. This unblinded study failed to show that the efficacy of transdermal fentanyl delivered by means of iontophoresis is equal to that of intravenous morphine for patient-controlled analgesia; (3) The adverse effects of transdermal fentanyl are those of all opiates, plus cutaneous reactions at the application site; (4) This transdermal system is not particularly convenient: the device is no simpler for patients to use than a pump for intravenous administration. There is also a risk of misuse and overdose: the number of doses per push cannot be verified, there is no lockout period between two button pushes, special precautions must be taken when washing, and the used devices still contain fentanyl; (5) In practice, intravenous delivery remains the standard method of patient-controlled postoperative acute pain relief.