From codeine to transdermal fentanyl for cancer pain control: a safety and efficacy clinical trial

Fentanyl is a synthetic opioid, suitable for transdermal delivery, offering an interesting solution as a step 3 opioid in cancer pain treatment. The purpose of the study was to carefully investigate: 1) the feasibility of the direct conversion from codeine to TTS fentanyl, in patients already receiving codeine and requiring strong opioids for their analgesia; 2) the safety of 25 microg/hour incremental steps and at shorter than 72-hour intervals, if clinically required.

130 patients were judged eligible for the study. All the patients were receiving 280-360 mg or more of codeine and required strong opioid for their analgesia. The study lasted 56 days. The initial dose was 25 microg/hour. TTS fentanyl for all patients. Data assessments were made on baseline, day 1, day 2, day 3, in the hospital and thereafter on days 7, 14, 21, 28, 42 and 56. After the patch application, all the patients were given an immediate release oral morphine (5 mg) every 4-6 hours for the first 12 hours and then if needed only as rescue doses. The patients remained in the hospital for the first three days of the study where follow-up (pain score, satisfaction, side effects etc.). was recorded by the palliative care team and by daily cards.

The itnitial dose of fentanyl was 25 microg/hour while the mean dose on day 3 was 45.9 microg/hour. All the patients required upward titration of the study medication during follow-up visits. On day 56 the mean dose of fentanyl was 87.4 microg/hour. Mean pain intensity decreased from an initial 5.96 on the baseline to 0.83 on day 3. Karnofsky scale measurements between treatment phases revealed non-significant changes. The rate of overall satisfaction was quite high. Nine patients discontinued the study due to inadequate pain relief or side effects between day 7 and day 28, while five patients died between day 28 and day 56. Constipation, nausea and vomiting were the most common side effects. Skin reaction was relatively mild and acceptable during the study.

Under controlled conditions, TTS fentanyl seems to be feasible for direct conversion from mild to strong opioids and additionally, 25 microg/hour incremental steps day by day can be made by palliative care specialists, if clinically required for cancer pain management.