Transdermal delivery systems for administering sufentanil through the skin areprovided. The systems contain a sufficient amount of sufentanil to induce andmaintain a constant state of analgesia when applied to a subject. The systemsare characterized as having one or more features including a high degree ofdosage form rate control over flux of sufentanil from the system, a high netflux of sufentanil from the system through the skin, lack of a permeationenhancer, an adhesive member demonstrating superior shear time, a lowcoefficient of variation in the net flux of sufentanil from the system, a highdelivery efficiency, and a substantially constant steady state net flux ofsufentanil from the system. Methods of using the transdermal delivery systemsto administer a sufficient amount of sufentanil to induce and maintainanalgesia for extended periods when applied to a subject are also provided.
