Efficacy and safety evaluation of once-daily OROS hydromorphone in patients with chronic low back pain: a pilot open-label study (DO‑127)

ABSTRACT

Objective: To evaluate the safety, tolerability, and efficacy of once-daily osmotic controlled-release oral delivery system (OROS) hydromorphone in patients with chronic low back pain of moderate-to-severe intensity.

Research design and methods: This was a 6-week, multicenter, nonrandomized, noncomparative, open-label, repeat-dose study of chronic (≥ 6 weeks) low back pain. The study comprised three periods: prior opioid stabil­ization (2–7 days); OROS hydromorphone conversion, titration, and stabilization (3–14 days); and OROS hydro­morphone maintenance (28 days). Patients were evalu­ated weekly. Baseline pain assessment was performed at the end of prior opioid stabilization. For pain relief rating, endpoint was defined as the mean pain relief score from the last 2 nonmissing days before study termination. For other assessments, endpoint was defined as the last post-baseline evaluation.

Results: Of the 207 patients who received the study drug, 131 completed the trial. Scores (mean ± SD) for Brief Pain Inventory ‘worst pain in the last 24 hours’ decreased significantly from baseline to endpoint (–0.8 ± 2.06, p < 0.0001). The proportions of patients and investigators rating the global effectiveness as good, very good, or excellent increased from 31.6% at baseline while patients were on prior opioids to 63.2% at endpoint while patients received OROS hydromorphone, and from 29.8% at baseline while patients were on prior opioids to 65.8% at endpoint while patients received OROS hydromorphone, respectively. Daily pain relief ratings also increased significantly (+0.26 ± 1.084, p = 0.0008). Significant improvements in health-related quality of life and sleep problems were observed. Adverse events were mild to moderate in severity; the most common of these were constipation, nausea, headache, and somnolence. The limitations of this study include its pilot-type design and the lack of comparison of OROS hydromorphone with a placebo or another drug. Additional comparative and longer-term studies are needed to confirm these findings.

Conclusions: OROS hydromorphone may be an effective treatment for chronic low back pain of moderate-to-severe intensity. Adverse events were typical of those associated with opioid therapy.

Key words: :

• Chronic low back pain
• Hydromorphone
• Opioid
• OROS