Transdermal fentanyl in the long-term treatment of cancer pain: a prospective study of 50 patients with advanced cancer of the gastrointestinal tract or the head and neck region.

This open prospective study evaluated the combination of initial dose titration with patient-controlled analgesia (PCA) and long-term treatment with transdermal fentanyl in 50 cancer patients requiring opioids for severe pain. The delivery rate of the first transdermal therapeutic system (TTS) was calculated from the self-administered intravenous fentanyl dose during the first 24 h. TTS were changed every 48-72 h, and a different patch size was chosen if necessary. Pain intensity (101-step numeric analog scale) and side-effects were assessed daily. The patients were treated for 66 +/- 101 days (range 3-535 days). The average delivery rate was 5.9 +/- 4.1 mg/d. Mean pain intensity decreased from initially 45 +/- 21 to 19 +/- 15 in the titration phase and 15 +/- 11 during long-term treatment. Three patients showed moderate respiratory depression. Other severe side-effects were not observed. Patient compliance and acceptance were excellent. The results suggest that intravenous PCA is useful for initial dose finding, and transdermal fentanyl is effective and safe during long-term treatment of cancer pain.