Analgesic effects of switching from oral morphine to transdermal fenanyl in cancer patients

Objective To evaluate the analgesic and side effects of switching from Oral morphine to transdermal fentanyl on patients with advanced cancer pain.Methods Forty patients with cancer pain who failed to achieve adequate pain control were converted from oral morphine to transdermal fentanyl.A dose ratio with oral morphine/transdermal fentanyl of 100∶1(mg) daily was calculated.Pain intensity was rated by Visual Analogue Scale(VAS).Clinically obvious pain control was defined as a decrease≥2 points in pain intensity.The presence of side effects was evaluated as absent(0),mild(1),moderate(2)or severe(3).Results Pain intensity decreased significantly after switching.The mean pain score decreased from 5.7 to 3.4 on 7 day after switching.One or more side effects occurred in 37(92.5%)patients before switching and in 25(62.5%)patients after switching.Conclusion Switching from oral morphine to Transdermal fentanyl is an effective and safe clinical analgesic strategy for terminal cancer patients.