A Cochrane review [withdrawn from publication] included 4 studies with a total of 393 subjects. All concerned oral transmucosal fentanyl citrate (OTFC). OTFC was superior to placebo, normal release morphine, and previous rescue medication with a weighted mean difference (WMD) of –0.68 (95% CI –1.03 to –0.34) for pain intensity at 15 mins and WMD –0.91 (95% CI –1.23 to –0.59) for pain intensity at 30 mins. OTFC was superior in providing pain relief at 15 mins, WMD 0.54 (95% CI 0.40 to 0.69) and 30 mins WMD 0.61 (95% CI 0.47 to 0.75); and superior global performance (compared to previous rescue medication and placebo) WMD 0.76 (95% CI 0.58 to 0.95). No trials were found for other opioids.