Rapid onset opioids for breakthrough pain: Titrating or not titrating,this is the question!

Breakthrough cancer pain (BTcP) has been defined as a transitory increase in pain intensity that occurs either spontaneously, or in relation to a specific predictable or unpredictable trigger, despite relatively stable and adequately controlled background pain.Traditional dosing recommendations for BTcP have suggested that the effective dose of oral opioids should be a percentage of a patient’s total daily opioid dose. In the last years a number of new formulations that deliver fentanyl directly through mucous membranes have been developed in an effort to provide a more rapid onset of effect (rapid onset opioids, ROOs). Recent recommendations suggest that the dose of ROOs for BTcP should be determined by individual titration. However, the need of titrating ROOs doses for BTcP may make the practical use of these drugs difficult in the daily activity, particularly at home or in outpatients. The question of how to dose ROOs for BTcP remains controversial.The aim of this review was to analyze the robustness of the statement that dose of ROOs should be titrated for BTcP, assessing controlled studies of ROOs for BTcP. From the available literature there are no consistent data to recommend dose titration of ROOs for BTcP.Randomized studies with an appropriate design comparing advantages and disadvantage of ROOs titration versus fixed doses proportional to around the clock opioid doses should provide the answer to this question.