Background: Chronic pain has a marked negative impact on quality of life. Opioid treatment is often effective in controlling this pain, but it has numerous side-effects, particularly affecting bowel function.
Objective: The objective of the study was to evaluate the efficacy and safety of combined prolonged-release (PR) oxycodone and naloxone for the treatment of chronic pain under conditions of daily practice.
Research design and methods: This is a multi-center, prospective, non-interventional, observational study. Analgesic efficacy and bowel function were assessed in patients suffering from long-lasting, severe chronic pain of different etiology (cancer and non-cancer) treated with combined PR oxycodone/PR naloxone and observed for 4 weeks. Pain was evaluated using the Brief Pain Inventory (BPI-SF) and constipation symptoms due to opioid treatment using the Bowel Function Index (BFI). Descriptive data are presented based on observed cases, efficacy and tolerability data additionally based on completely documented patients (for each parameter at least more than 2000 patients).
Trial registration: This trial was registered with the German Federal Institute for Drugs and Medical Devices (BfArM), study code: OXN9002.
Results: A total of 7836 patients were recruited in 6496 centers. Strongest pain was reduced by an average of 2.9 points on an 11-point numeric rating scale (p < 0.001, evaluation populations n = 4271 or 2454, respectively). A progressive rise of patients without pain during the 24 hours prior to each evaluation (first visit, 11.6%; final visit, 33.8%; p < 0.001, evaluation populations n = 4413 or 3014, respectively) was observed. Bowel function improved significantly, indicated by a decrease of the bowel function index from 38.2 +/- 30.9 to 15.1 +/- 18.6 (p < 0.001, evaluation population n = 7640 or 6769, respectively) on a numeric scale of 0-100. Opioid-pretreated patients presented a marked decrease of constipation from 71% at the first visit to 34.1% at the final visit (p < 0.001, evaluation populations n = 5751 or 5123, respectively). Efficacy and tolerability were reported as good or very good by 84% and 87% of patients (evaluation populations n = 7590 and 7577, respectively). There were 4526 adverse events in 1566 patients (20.0%) with 3386 classified as adverse drug reactions; 177 patients (2.3%) suffered serious adverse events which were classified as serious adverse drug reactions in 51 cases.
Conclusions: PR oxycodone/PR naloxone achieved good pain control and significantly reduced constipation and associated opioid-induced gastrointestinal symptoms in this observational 4-weeks-trial.