RESUMEN
Formulations of fentanyl that use buccal, sublingual, or nasal transmucosal routes of administration have been developed for the treatment of BTP in opioid-tolerant patients with cancer. The purposes of this analysis were to identify and review published data describing the efficacy and safety of different oral or nasal transmucosal fentanyl formulations for treatment of cancer-related BTP, based on a critical analysis of scientific literature. Oral transmucosal or intranasal fentanyl is an effective treatment for management of BTP episodes due to a potent analgesic effect, rapid onset of action, and sustained effect. Furthermore, it is a reasonably safe treatment, causing generally mild adverse events not leading to treatment discontinuation. Nevertheless, further progress in standardizing methodology, definitions, and criteria used both in research and in clinical practice is needed in order to generate quality information allowing a better understanding of the comparable efficacy of available formulations of fentanyl. A more rigorous assessment of long-term safety is also needed to establish a balance between benefits and risks of the available options.