Comparison of oral controlled-release morphine with transdermal fentanyl in terminal cancer pain

Controlled-release morphine (MST) given twice daily provides a simpler and more convenient treatment regimen than 4-hourly opioid administration for the control of cancer pain. Recently, a new formulation of transdermal fentanyl (TDF) has been developed which provides a new route for the treatment of cancer pain. The present study was designed to compare the analgesic efficacy, safety and adverse effects of MST and TDF in the management of chronic cancer pain.

In this open, comparative and randomized study, patients were treated with oral morphine hydrochloride immediate-release (MHIR) in the stabilization phase and then the prescription was switched to MST or TDF for 14 days in the treatment phase. Oral MHIR was provided as rescue medication for breakthrough pain. Assessments of the pain intensity, pain frequency, degree of pain improvement, profile of mood states, quality of sleep, activity status and adverse effects were performed before and after the stabilization phase and before and after the treatment phase.

Forty of 47 cancer patients completed the study with 20 patients in each group. There were significant (p < 0.05) improvements in pain intensity, pain frequency, mood states and quality of sleep in both groups before and after treatment, while improvement in the activity status was not significant. No specific adverse effects were encountered except for drowsiness which occurred in 6 patients treated with MST and 5 treated with TDF (p < 0.05). Insomnia was significantly improved (p < 0.05) with both regimens compared with that in the period before treatment. There were no significant differences between the two study groups in analgesic efficacy or adverse effects.

These results suggest that TDF and MSt are safe and effective analgesics for the management of chronic cancer pain. However, TDF provides a simpler and more convenient treatment for those patients with severe nausea, vomiting or dysphagia.