Fixed-ratio combination oxycodone/naloxone compared with oxycodone alone for the relief of opioid-induced constipation in moderate-to-severe noncancer pain.

Opioid therapy is frequently associated with treatment-limiting constipation. Naloxone is an opioid antagonist with low oral systemic bioavailability. This Phase III clinical trial assessed the safety and efficacy of an oral fixed-ratio combination of oxycodone prolonged-release (PR) and naloxone PR compared with oxycodone PR in relieving opioid-induced constipation. This double-blind, multicenter trial was conducted in specialist and primary care centers in four European countries in an out-patients setting. The study included 322 adult patients with moderate-to-severe, noncancer pain requiring opioid therapy in a range of >or=20 mg/day and