Changes in the prescribed daily doses of transdermal fentanyl and transdermal buprenorphine during treatment of patients with cancer and noncancer pain in Germany: Results of a retrospective cohort study

Background: During long-term therapy with strong oploids (step III opiolds according to the World Health Organization [WHO] analgesic ladder), dose increases are often necessary because of deterioration of the primary disease or development of tolerance. Objective: The purpose of this study was to compare changes in dosages of transdermal (TD) fentanyl and TD buprenorphine in patients with cancer and noncancer pain. Methods: In a retrospective study, patients with cancer and noricancer pain being treated with TD fentanyl or TD buprenorphine for at least 3 months between January 2001 and December 2003 were identified from the IMS Disease Analyzer-mediplus database, which contains all patient-related data documented from 400 medical practices in Germany. The indications for treatment were defined according to the International Classification of Diseases, 10th Revision, and included neoplasm (cancer groups), and osteoarthritis, low back pain, and osteoporosis (noncancer groups). The cohort patients were considered to have comparable pain intensity because they had received similar analgesic premedication classified according to steps I to III of the WHO analgesic ladder (cohort groups). The mean prescribed daily doses on first and last prescription were documented, and the mean percentile increases were calculated over the whole treatment duration and per day. Additionally, the mean percentile intraindividual increases (on a per-patient basis) were estimated. Results: The cohort groups consisted of 448 patients with noncancer pain and 446 patients with cancer pain (552 women and 342 men; mean age, 74 years; range, 25-101 years). The mean percentile increases in dosages over the whole treatment duration and adjusted per day were significantly higher in patients taking TD fentanyl (P < 0.05). Differences were even greater for the mean percentile intraindividual increases per day, which totaled 0.42% and 0.17% for cancer patients taking TD fentanyl and TD buprenorphine, respectively; corresponding values were 0.25% and 0.09% in noncancer patients (P < 0.001). Conclusions: This retrospective analysis showed a significantly higher increase in the mean daily doses of TD fentanyl as compared with TD buprenorphine. The results must be verified in prospective, randomized clinical studies.