A comprehensive review of rapid-onset opioids for breakthrough pain. (1/4)

Efficacy of rapid-onset oral fentanyl formulations vs. oral morphine for cancer-related breakthrough pain: a meta-analysis of comparative trials. (2/4)

Fentanyl for the treatment of tumor-related breakthrough pain. (3/4)

The use of Instanyl(R) in the treatment of breakthrough pain in cancer patients: a 3-month observational, prospective, cohort study. (4/4)