Gastrointestinal symptoms under opioid therapy: a prospective comparison of oral sustained-release hydromorphone, transdermal fentanyl, and transdermal buprenorphine.

Introduction: The purpose of this trial was to evaluate the effect of long-term treatment with oral sustained-release hydromorphone, transdermal fentanyl, and transdermal buprenorphine on nausea, emesis and constipation.

Patients And Methods: Randomly selected outpatients with cancer pain receiving one of the study medications were enrolled in a prospective, open-labeled, controlled trial (n=174). Mobility, pain, and gastrointestinal symptoms were assessed directly and per selected item on the ECOG (Eastern Cancer Oncology Group), EORTC (European Organisation for Research and Treatment of Cancer) questionnaires, NRS (Numerical Rating Scales), and analyzed statistically.

Results: Demographic and medical data were comparable in all groups. Only 15% of patients suffered from constipation. 59% took the prescribed laxatives. The incidence of stool free periods >72 h was significantly higher with transdermal opioids (transdermal fentanyl: 22%; transdermal buprenorphine: 21%; oral hydromorphone: 2%; p=0.003). 21% of patients revealed nausea and emesis. The mean NRS for nausea (transdermal fentanyl:1.3; transdermal buprenorphine: 1.2; oral hydromorphone: 1.5; p=0.6), the consumption of antiemetics (transdermal fentanyl: 42%; transdermal buprenorphine: 33%; oral hydromorphone: 36%; p=0.6) and laxatives (transdermal fentanyl:53%; transdermal buprenorphine:66%; oral hydromorphone: 61%; p=0.2) did not differ significantly, in contrast to the score for emesis (transdermal fentanyl: 16%; transdermal buprenorphine:13%; oral hydromorphone: 33%; p=0.02). Morphine equivalent opioid doses differed (mg/d transdermal fentanyl: 183; transdermal buprenorphine: 89; oral hydromorphone: 143; p=0.001), because of obvious tolerance varying after long-term treatment.

Conclusions: Gastrointestinal symptoms of cancer pain patients undergoing an opioid therapy are related to multifactorial causes. Transdermal opioids showed no benefit over oral controlled-release hydromorphone with regard to gastrointestinal symptoms. The conversion ratios for transdermal fentanyl, transdermal buprenorphine, and oral hydromorphone did not accord to the literature, because of differing occurrences of opioid tolerance after long-term therapy.