Radbruch, L., Sabatowski, R., Loick, G., Kulbe, C., Kasper, M., Grond, S., & Lehmann, K.A. (2000). Constipation and the use of laxatives: A comparison between transdermal fentanyl and oral morphine. Palliative Medicine, 14, 111–119.
To investigate constipation and the use of laxatives in patients with chronic cancer pain treated with oral morphine and transdermal fentanyl.
Patients were switched from long-acting morphine to fentanyl patches. Fentanyl doses were calculated with a conversion table based on a 100:1 dose ratio. If the calculated fentanyl dose was higher than 2.4 mg/day = 100 ug/hour (more than 270 mg/day slow-release morphine), more than one patch was used. Patients were treated with oral slow-release morphine for at least six days (morphine phase) until they reported stable pain intensity scores of 40 or less on a visual analog scale (0 = no pain, 100 = worst pain imaginable) for at least two days. Analgesic therapy then was switched from oral morphine to transdermal fentanyl (fentanyl phase). Fentanyl patches were changed regularly after three days. Fentanyl doses were increased when patients reported inadequate pain relief or had to take more than six rescue medications per day. The study was terminated after 30 days of transdermal therapy. Patients who completed the study until day 17 or longer were included in an intraindividual comparison of laxative intake using the Wilcoxon rank test.
This was an open, sequential, multi-center study.
The use of laxatives was reduced significantly with transdermal fentanyl.