Clinical pharmacy
-
The physicochemical properties, pharmacology, pharmacokinetics, serum concentrations and clinical effects, adverse effects and contraindications, and dosage of transdermally administered fentanyl are described, and clinical studies evaluating the use of a transdermal fentanyl system in the treatment of postoperative pain and chronic cancer-associated pain are reviewed. After application of a transdermal system, fentanyl is absorbed into the skin beneath the patch, where a depot forms in the upper skin layers. Plasma fentanyl concentrations are barely detectable for about two hours after patch placement. ⋯ The 25-micrograms/hr patch should be used for initial treatment in patients not previously treated with narcotics. The dosage may be gradually increased until effective analgesia is obtained. Although experience with the product is limited, transdermally administered fentanyl appears to be effective for the long-term management of cancer-related pain.