The use of low doses of a sublingual fentanyl formulation for breakthrough pain in patients receiving low doses of opioids.

OBJECTIVE: The aim of this study was to prospectively assess the efficacy and safety of low doses of sublingual fentanyl (SLF) for the treatment of breakthrough pain (BTP) in cancer patients in patients who were receiving low opioid doses for background analgesia.

METHODS: A sample of cancer patients presenting BTP episodes and receiving stable low doses of opioids for background pain (less than 60 mg of oral morphine equivalents) was selected to assess the efficacy and safety of low doses of SLF (67 μg). For each patient, data from four consecutive episodes were collected. For each episode, changes in pain intensity and adverse effects when pain got severe (T0), and 5, 10, and 15 min after SLF administration (T5-T30) were recorded. The occurrence of serious effects occurring within 2 h of SLF administration were also considered.

RESULTS: Fifty-one patients were recruited for the study. The mean age was 66.8 (SD 12.9). A mean of 3.3 episodes/patient were recorded. Four patients did not have episodes of BTP. 147 episodes were evaluated. Six episodes (4.1 %) required a rescue medication at T30. Pain intensity significantly decreased at T5, T10, T15 and T30 (p < 0.0005 in all cases). A high percentage of patients had a pain reduction of more than 33 and 50 % at T5, T10, T15 and T30. Adverse effects were mild and generally already present, due to basal opioid treatment or disease. No serious adverse effects were observed for the subsequent 2 h.

CONCLUSION: This study suggests that SLF given in low doses in patients receiving lower doses of opioids for background analgesia is safe and effective in clinical practice.