Background: Slow release (SR) opioids around the clock are the mainstay for moderate to strong cancer pain. This recommendation is not scientifically based. Therefore, a phase 1 pilot study of rapid acting nasal fentanyl (NF) taken on demand as the only opioid for cancer pain to explore feasibility and safety aspects was launched.
Methods: Patients with cancer, naïve to strong opioids but in need of such drugs, were included. They received a test dose of NF before titration (1-5 days) was started. Ten days treatment was followed by 7 days of observation after switching to SR morphine. Pain relief, nausea, sedation, and local irritation were assessed (11-point numeric rating scale [NRS]). Other adverse events (AEs) were also recorded by the patient. Investigator had regular patient telephone contact.
Results: Ten patients were included. The test dose was well tolerated. Venous fentanyl concentrations at 11 minutes after the test dose differed considerably. All subjects completed the titration; six patients the treatment phase. Three serious AEs were reported; all due to hospitalization, none related to NF. A possible adverse drug reaction (hearing abnormalities) was reported. Other adverse effects were minor. NF treatment reduced average pain for the whole group compared to baseline (4.6-3.7 on the 11-point NRS) and pain relief was achieved in 187/230 (81 percent) of NF administrations (reduction of 2 or more on the 11-point NRS 15 minutes after NF administration).
Conclusion: This explorative study suggests that it is reasonable that the concept of treating pain in patients with cancer using NF on demand can undergo controlled clinical studies.