Oral transmucosal fentanyl citrate in the management of breakthrough pain in cancer: an open, multicentre, dose-titration and long-term use study.

Sixty-six patients with cancer-related pain entered an open multicentre study to examine the safety and efficacy of oral transmucosal fentanyl citrate (OTFC) in the treatment of breakthrough pain. Patients were eligible for the study if they were stabilized on a long-acting opioid but were experiencing up to four episodes of breakthrough pain a day and achieving at least partial relief from breakthrough pain using conventional medication (normal release oral morphine in the majority of patients). The efficacy of the conventional medication was documented in a run-in phase and patients then changed to OTFC. All patients were treated initially with a 200 mcg unit of OTFC and the dose was increased if necessary to a level that produced relief of breakthrough pain without troublesome adverse effects. Fifty-eight patients completed the run-in phase using their usual medication and entered the dose titration phase with OTFC and 57 patients received at least one dose of OTFC. Forty-two patients (72%) found a successful dose of OTFC. The primary outcome measures were the Summed Pain Intensity Differences (SPID) and Total Pain Relief (TOTPAR) scores at 60 min. There was a significant difference in both measures in favour of OTFC compared with conventional medication in these patients. Twenty-eight of the 42 patients (67%) preferred OTFC to their usual medication. The most common adverse effects attributed to OTFC were nausea, stomatitis, vomiting and dizziness but there were no unpredicted or severe problems. Thirty-seven patients continued into the long-term study and 12 of these completed six months treatment. Most drop-outs in this phase were associated with progression of the underlying disease. No patient stopped using OTFC because of dissatisfaction with the drug. OTFC appears to be a safe and effective treatment for breakthrough pain in cancer patients and may have advantages over currently available opioid formulations.