Efficacy and safety of transdermal fentanyl and sustained-release oral morphine in patients with cancer and chronic non-cancer pain.

PURPOSE: To evaluate effectiveness and safety information of transdermal fentanyl (TDF) (Duragesic/Durogesic) and sustained-release oral morphine (SRM) in cancer pain (CP) and chronic non-cancer pain (NCP), a pooled analysis was conducted on datasets of published, open label, uncontrolled (no comparator group) and randomised controlled (with SRM as comparator) studies of TDF.

PATIENTS AND METHODS: Eight trials with treatment durations of at least 28 days met the inclusion criteria. The effectiveness analysis assessed changes in average pain and pain 'right now' scores between baseline and Day 28. The safety analysis evaluated the incidence of adverse events (AEs) reported within the first 28 days of treatment with TDF or SRM. Subgroup analyses included pain type, gender, age, weight, and body mass index.

RESULTS: Pooled efficacy data were available from 1220 patients; these showed that both TDF and SRM were effective in improving pain 'right now' scores (0-100 scale) from baseline to Day 28. The improvement was significantly more pronounced in the TDF treatment group (-26.7 +/- 31.3 for TDF, -18.7 +/- 30.9 for SRM, p = 0.002). This favourable effect of TDF was most apparent amongst patients with NCP. Data concerning AEs were available from over 2500 patients with CP (3 out of 10 patients) or chronic NCP (7 out of 10 patients). Significantly fewer patients in the TDF than in the SRM group reported any AE (72% vs. 87% respectively; p < 0.001), or an AE leading to the study drug being permanently discontinued (16% vs. 23% respectively; p < 0.001). Constipation and somnolence occurred considerably less frequently in the TDF than in the SRM treatment group. This difference was statistically significant in both the CP and NCP subgroups.

CONCLUSION: This pooled data analysis provides expanded insight into the safety and effectiveness profile of transdermal fentanyl in patients with chronic pain. It shows significantly improved pain relief with transdermal fentanyl compared with sustained-release oral morphine, and supports current evidence of favourable tolerability of transdermal fentanyl, particularly with regard to reduced constipation and somnolence.