Objective: To evaluate the efficacy and safety of oral lubiprostone for relieving symptoms of opioid-induced constipation (OIC) in patients with chronic noncancer pain.
Design: Prospective, randomized, double-blind, placebo-controlled trial.
Setting: Seventy-nine US and Canadian centers.
Subjects: Patients aged ≥ 18 years with OIC, defined as <3 spontaneous bowel movements (SBMs) per week.
Methods: Patients received lubiprostone 24 mcg or placebo twice daily for 12 weeks. The primary endpoint was change from baseline in SBM frequency at week 8.
Results: Among randomized patients (N=418; lubiprostone, N=210; placebo, N=208), most completed the study (lubiprostone, 67.1%; placebo, 69.7%). The safety and efficacy (intent-to-treat) populations included 414 (lubiprostone, N=208; placebo, N=206) and 413 (lubiprostone, N=209; placebo, N=204) patients, respectively. The mean (standard deviation) age was 50.4 (10.9) years; most patients were female (64.4%) and white (77.7%). Changes from baseline in SBM frequency rates were significantly higher at week 8 (P=0.005) and overall (P=0.004) in patients treated with lubiprostone compared with placebo. Pairwise comparisons showed significantly greater overall improvement for abdominal discomfort (P=0.047), straining (P<0.001), constipation severity (P=0.007), and stool consistency (P<0.001) with lubiprostone compared with placebo. Moreover, patients rated the effectiveness of lubiprostone as significantly (P<0.05) better than placebo for 11 of 12 weeks. The most common treatment-related adverse events (AEs) with lubiprostone and placebo were nausea (16.8% vs 5.8%, respectively), diarrhea (9.6% vs 2.9%), and abdominal distention (8.2% vs 2.4%). No lubiprostone-related serious AEs occurred.
Conclusion: Lubiprostone effectively relieved OIC and associated signs and symptoms and was well tolerated in patients with chronic noncancer pain (http://clinicaltrials.gov/ct2/show/NCT00595946).
Keywords: Bowel Movement; ClC-2; Opioid; Opioid-Induced Constipation; Placebo-Controlled Trial; Prostone.
© 2014 The Authors. Pain Medicine published by Wiley Periodicals, Inc. on behalf of American Academy of Pain Medicine.