Use of TTS Fentanyl as a Single Opioid for Cancer Pain Relief: A Safety and Efficacy Clinical Trial in Patients Naive to Mild or Strong Opioids

<jats:p>Background: Up to now, a transdermal therapeutic system (TTS) of fentanyl has been applied to cancer patients on opioid analgesics previously treated with mild opioids or morphine. The aim of this study was to investigate the efficacy and safety of TTS fentanyl (patch) administration as an analgesic to patients treated with opioid analgesics for moderate-to-severe cancer pain, with immediate-release oral morphine only as rescue medication. The prior analgesic medication of the patients did not include mild or strong opioids. Methods: The study group consisted of 113 patients (54 men and 59 women; age range: 21–87 years, mean ± SD 61.3 ± 14.84 years) with undertreated chronic cancer pain. The study period was 42 days. The patients were hospitalized for the first 3 days of the study; thereafter they were transferred to their home for the rest of the study. Daily cards were completed, noting their pain score (0–10 VAS), nausea, vomiting, constipation, skin reactions, dizziness or any other complaints. Vital signs were also recorded. Data assessments were made at baseline, on days 1, 2 and 3 (during hospitalization) and thereafter on days 7, 14, 21, 28, 35, and 42 after hospital discharge. The initial TTS fentanyl delivery rate was chosen depending on the patient’s analgesic requirements. All patients were given an oral morphine solution (5–10 mg), every 4–6 h, for the first 12 h, as rescue medication. Results: Baseline pain score was between 6 and 10 (mean ± SD 7.1 ± 1.7). The initial TTS fentanyl delivery rate was between 25 and 50 µg/h (mean ± SD 36.5 ± 15.7). On day 3, 95 patients (84%) reported a pain score ≤3 (mean ± SD 0.5 ± 0.8), 14 patients (12.4%) a pain score of 4 and 4 patients (3.5%) of 5–8. No adverse effects suggesting the discontinuation of the study were reported. From day 7 until the completion of the study, the mean pain score was between 1.3 and 0.16 while the TTS fentanyl delivery rate on day 42 was between 25 and 400 µg/h (mean ± SD 122.1 ± 81.2 µg/h). Conclusion: Analgesic treatment with TTS fentanyl used as a single opioid is effective and safe for cancer pain relief, given that is cautiously applied, in patients requiring strong opioid analgesics even if they were naive to strong or mild opioids.</jats:p>