Stage I: dose-response relationship and safety assessment of inhaled fentanyl aerosol in patients with breakthrough cancer pain. placebo-controlled, cross-over, double-blind randomized design is applied in this stage.~Patients meeting the inclusion/exclusion criteria will be treated with inhaled fentanyl aerosol (4 of 6 episodes BTcp) or placebo (2of 6 episodes BTcp).Subjects will inhale fentanyl aerosol or placebo for each episode of BTcp with a starting dose of 25 µg every 4 minutes until adequate pain alleviation. The maximum doses are 6×25 µg.~Stage II: The dosage regimen (number of puffs) will be depended on the data from Stage I. Subjects will inhale fentanyl aerosol not in the episode of breakthrough cancer pain with a starting dose of 25 µg every 4 minutes.
Breakthrough cancer pain (BTcP) is a common problem in patients with cancer. This is a phase I/IIa, pharmacokinetic, dose-response and safety study of inhaled fentanyl aerosol (25µg/dose) in Chinese patients with breakthrough cancer pain. The study will include two stages.