Morphine remains gold standard in breakthrough cancer painBMJ 2008; 337 doi: http://dx.doi.org/10.1136/bmj.a3104 (Published 24 December 2008) Cite this as: BMJ 2008;337:a3104
Although Davies and colleagues argue that little evidence supports the unlicensed use of oral morphine,1 morphine remains the gold standard in cancer pain. Licensed or unlicensed use is a transient status, especially in palliative care. Little evidence may support the use of oral morphine in breakthrough pain,1 but oral transmucosal fentanyl citrate compared with morphine showed a slight statistical superiority but no clinical difference in pain at 15 and 30 minutes.2
The systematic review by Zeppetella and Ribeiro that Davies and colleagues cite may also be biased in relation to the general utility of oral transmucosal fentanyl citrate.3 Only one of the four papers reviewed compared fentanyl with oral morphine. The others were placebo and dose titration studies. We think that the systematic review should have included only papers comparing fentanyl with another active opioid, preferably morphine. And does combining the results of such different trials make clinical sense? Indeed, the only randomised clinical trial included in the review comparing fentanyl with morphine showed no differences in effectiveness, but the combination of all the studies showed it as effective.
We agree with Ross and Riley that there are gaps in several areas of knowledge,4 but morphine’s clinical effectiveness in cancer pain isn’t one of them.
Cite this as: BMJ 2008;337:a3104
Competing interests: None declared.