Transdermal fentanyl: new preparation. An alternative to morphine

(1) Fentanyl, an opiate agonist, was previously available in injectable form for use in anaesthesia. The new patch form is indicated for the treatment of chronic cancer pain. (2) The clinical assessment mainly involved non comparative trials showing good analgesic efficacy on chronic pain. (3) Given the long time-lag before the effect of fentanyl is felt, a short-acting analgesic should be given when the first patch is applied. Once adequate relief has been achieved the patch can be used alone to treat chronic pain. It must be replaced every three days. (4) Fentanyl patches have similar adverse effects to opiate agonists, i.e. gastrointestinal and neuropsychological disorders. However, the adverse effects of morphine and fentanyl are not always identical in a given patient. (5) Fentanyl patches carry a risk of misuse by opiate addicts and of acute intoxication.