Effectiveness and gastrointestinal tolerability during conversion and titration with once-daily OROS® hydromorphone extended release in opioid-tolerant patients with chronic low back pain.

Purpose: To describe the efficacy and safety of hydromorphone extended-release tablets (OROS hydromorphone ER) during dose conversion and titration.

Patients And Methods: A total of 459 opioid-tolerant adults with chronic moderate to severe low back pain participated in an open-label, 2- to 4-week conversion/titration phase of a double-blind, placebo-controlled, randomized withdrawal trial, conducted at 70 centers in the United States. Patients were converted to once-daily OROS hydromorphone ER at 75% of the equianalgesic dose of their prior total daily opioid dose (5:1 conversion ratio), and titrated as frequently as every 3 days to a maximum dose of 64 mg/day. The primary outcome measure was change in pain intensity numeric rating scale; additional assessments included the Patient Global Assessment and the Roland-Morris Disability Questionnaire scores. Safety assessments were performed at each visit and consisted of recording and monitoring all adverse events (AEs) and serious AEs.

Results: Mean (standard deviation) final daily dose of OROS hydromorphone ER was 37.5 (17.8) mg. Mean (standard error of the mean [SEM]) numeric rating scale scores decreased from 6.6 (0.1) at screening to 4.3 (0.1) at the final titration visit (mean [SEM] change, -2.3 [0.1], representing a 34.8% reduction). Mean (SEM) change in Patient Global Assessment was -0.6 (0.1), and mean change (SEM) in the Roland-Morris Disability Questionnaire was -2.8 (0.3). Patients achieving a stable dose showed greater improvement than patients who discontinued during titration for each of these measures (P < 0.001). Almost 80% of patients achieving a stable dose (213/268) had a ≥30% reduction in pain. Commonly reported AEs were constipation (15.4%), nausea (11.9%), somnolence (8.7%), headache (7.8%), and vomiting (6.5%); 13.0% discontinued from the study due to AEs.

Conclusion: The majority of opioid-tolerant patients with chronic low back pain were successfully converted to effective doses of OROS hydromorphone ER within 2 to 4 weeks.