Background The value of opioids is recognised internationally in the management of chronic non-cancer pain (CNCP), and patient preference in relation to pain relief has become increasingly important in analgesic selection. When comparing opioids that have been titrated to effect we cannot logically expect to see much difference in efficacy.¹ Thus, patient preference, while important for all clinical decisions, deserves a special emphasis when treatment efficacies are comparable, or when therapies can markedly affect patients? quality of life.² The patient is, therefore, likely to be the best judge of the delicate balance between analgesic efficacy, side-effects and the overall pain experience. This reflects our choice of pragmatic outcome measures, such as quality of life and patient preference, in addition to pain measurements, for the clinical trials of opioids in CNCP.

Methods We report here the results of a large, multicentre, 8-week, randomised, two-way crossover trial (study A) of transdermal fentanyl (TDF; Durogesic®) versus sustained-release morphine (SRM; MS Contin®), in which patient preference, pain control, quality of life and adverse events were assessed in patients with CNCP (n = 256).³ Subsequently, an open-label, non-randomised, 12-month study (study B) of TDF evaluated the long-term use of TDF in CNCP patients (n = 532),⁴ of whom 103 had participated in study A.

Results In study A, 65.1% of patients preferred treatment with TDF to SRM (27.8%), with 7.1% expressing no preference. The main reason for preference was better pain relief, as more patients considered that pain control was ?good? or ?very good? with TDF than with SRM therapy (35% vs 23%, respectively, p = 0.002). Furthermore, patients using TDF generally had higher overall quality-of-life scores than those receiving SRM in each of the SF-36 categories with significant differences for bodily pain, vitality, social functioning and mental health categories (p < 0.005). The TDF group were less likely to experience constipation (48% vs 29%, respectively, p < 0.001) than those receiving SRM. In study B, treatment with TDF provided stable, sustained, long-term pain control in large numbers of patients. After initial dose titration, the mean TDF dose stabilised without the loss of analgesic efficacy (only 7% of patients withdrew because of insufficient pain relief). Thus, the development of tolerance to TDF was not a clinical problem. TDF treatment was preferred over previous opioid treatment by 69% of patients, primarily because of superior pain relief, followed by greater convenience and fewer adverse effects.

Conclusion Superior pain relief, less constipation and better quality of life were associated with TDF compared with SRM therapy. TDF was generally well tolerated and effective.

References

1. McQuay H. Lancet 1999;353:2229–32

2. Goodare H, Lockwood S. BMJ 1999;319:724–5

3. Allan L, et al. BMJ 2001, In press

4. Milligan K, et al. J Pain 2001, In press