Treatment with prolonged-release oxycodone/naloxone improves pain relief and opioid-induced constipation compared with prolonged-release oxycodone in patients with chronic severe pain and laxative-refractory constipation.

PURPOSE Laxative-refractory opioid-induced constipation (OIC) is defined as OIC despite using 2 laxatives with a different mechanism of action (based on the Anatomical Therapeutic Chemical Classification System level 4 term [contact laxatives, osmotically acting laxatives, softeners/emollients, enemas, and others]). OIC has a significant impact on the treatment and quality of life of patients with severe chronic pain. This noninterventional, observational, real-life study in Belgium investigated the efficacy of prolonged-release oxycodone/naloxone combination (PR OXN) treatment regarding pain relief and OIC compared with previous prolonged-release oxycodone (PR OXY) treatment for laxative-refractory OIC in daily clinical practice. METHODS Laxative-refractory OIC patients with severe chronic pain were treated with PR OXN for 12 weeks (3 visits). Pain relief (assessed on a numerical rating scale) and OIC (assessed by using the Bowel Function Index [BFI]) were evaluated at each visit. A responder was defined as a patient who had: (1) no worsening of pain at the last visit compared with visit 1 or a numerical rating scale ≤4 at visit 3/last visit; and (2) a reduction in BFI ≥12 units at visit 3/last visit compared with visit 1; or (3) a BFI ≤28.8 at visit 3/last visit. FINDINGS Sixty-eight laxative-refractory OIC patients with severe chronic pain (mean (sd) age 59.8 (13.3) years, 67.6% female and 91.2% non-malignant pain) were treated for 91 days with PR OXN (median daily dose, 20 mg). Treatment with PR OXN resulted in a significant and clinically relevant decrease of pain of 2.1 units (P < 0.001; 95% CI, 1.66-2.54) and of BFI by 48.5 units (P < 0.001; 95% CI, 44.4-52.7) compared with PR OXY treatment; use of laxatives was also significantly reduced (P < 0.001). Approximately 95% of patients were responders, and quality of life (as measured by using the EQ-5D) improved significantly. Adverse events were opioid related, and PR OXN treatment was well tolerated. IMPLICATIONS Treatment with PR OXN resulted in a significant and clinically relevant reduction in OIC compared with previous PR OXY treatment for these patients with severe chronic pain and laxative-refractory OIC. Treatment with PR OXN also resulted in a significant improvement in pain relief and quality of life. ClinicalTrials.gov identifier: NCT01710917.