Long-term treatment of cancer pain with transdermal fentanyl.

The long-term therapy of 51 patients using transdermal fentanyl was evaluated. The transdermal therapy was performed for 158 days (range, 15-855 days). The need for increasing dosages of transdermal fentanyl was caused by the progression of the underlying cancer disease (mean initial dose, 69.5 micrograms fentanyl/hr; mean final dose, 167.7 micrograms fentanyl/hr). The transdermal system was changed every third day. Application intervals had to be shortened in 23.5% of the patients. Pain reduction was good throughout the study. Severe side effects did not occur. Constipation and the need for laxatives occurred less frequently than with previously administered oral morphine. Skin tolerance of the transdermal system was good. The treatment of cancer pain with transdermal fentanyl can be performed as a long-term therapy and result in good pain relief. Considering its specific pharmacokinetic properties, it is an alternative medication on step III of the World Health Organization's guidelines for cancer pain management.