Evaluation of long-term efficacy and safety of transdermal fentanyl in thetreatment of chronic noncancer pain

The objective of this international, multicenter, open-label trial was to a ssess the efficacy and safety of up to 12 months of therapy with transderma l therapeutic system (TTS) fentanyl in patients (n = 532) with chronic nonc ancer pain. The trial was completed by 301 (57%) of the patients. The main outcome measures were pain control assessment, global treatment satisfactio n, patient preference for TTS fentanyl, and quality of life. The mean dose of transdermal fentanyl (TDF) increased from 48 to 90 mug/h during a period of 12 months. During treatment, on average 67% of patients within the effi cacy analysis group (n = 524) reported very good, good, or moderate pain co ntrol. Global satisfaction (very good or good) was also stable at 42%. The majority (86%) of patients reported a preference for TDF over their previou s treatment (P <.001, binomial test). Short Form 36 quality-of-life scores improved from baseline for bodily pain. The most frequent treatment-related adverse events were nausea (31%), constipation (19%), and somnolence (18%) . With regard to opioid-specific adverse events (respiratory depression [le ss than 1%], adrenal insufficiency [less than 1%], drug abuse/dependence [1 %], and opioid withdrawal syndrome [3%]), these were extremely rare and, wi th the exception of opioid withdrawal syndrome, none was considered definit ively related to the treatment. Long-term treatment with TDF provided a sta ble degree of pain control in the majority of patients with moderate to sev ere chronic noncancer pain. It was preferred by the majority of patients co mpared with their previous opioid medication. Overall, long-term treatment with TDF was generally well tolerated, particularly in view of the low inci dence of potentially serious side effects such as drug abuse/dependence and respiratory depression. However, at present, it is important that patients receiving TDF should still be subject to careful assessment and monitoring . (C) 2001 by the American Pain Society.