Randomized, double-blind, placebo-controlled study of the efficacy and safety of biphasic immediate-release/extended-release hydrocodone bitartrate/acetaminophen tablets for acute postoperative pain.

Background: A fixed-dose combination biphasic immediate-release (IR)/extended-release (ER) hydrocodone bitartrate (HB)/acetaminophen (APAP) tablet is being developed for the management of acute pain severe enough to require opioid treatment and for which alternative treatment options are inadequate.

Methods: This Phase III, randomized, double-blind, placebo-controlled, parallel-group study evaluated the analgesic efficacy and safety of IR/ER HB/APAP (n = 201) versus placebo (n = 202) over a period of 48 hours in patients with acute moderate to severe pain following unilateral bunionectomy. Patients received three tablets of placebo or IR/ER HB/APAP as an initial dose (hour 0) followed by two tablets every 12 hours for a total daily dose of 37.5/1625 mg HB/APAP on day 1 and 30/1300 mg HB/APAP thereafter. The primary efficacy outcome was the summed pain intensity difference (SPID) over the first 48 hours (SPID48) after the first dose.

Results: SPID48 was significantly greater with IR/ER HB/APAP versus placebo (p < 0.001). SPID dosing interval analyses demonstrated consistent, superior pain relief with IR/ER HB/APAP for each dosing interval (all p < 0.001). Mean PID was greater with IR/ER HB/APAP versus placebo beginning 30 minutes after the first dose (p < 0.05), and IR/ER HB/APAP demonstrated faster median time to the onset of perceptible, meaningful, and confirmed pain relief (all p < 0.001). Mean total pain relief scores also indicated greater pain relief with IR/ER HB/APAP versus placebo throughout the 48-hour period (p = 0.012) for all comparisons. A greater proportion of IR/ER HB/APAP versus placebo patients was either "very satisfied" or "satisfied" with their pain relief (69.3% vs 49.4%; p < 0.001). Nausea was the most common treatment-emergent adverse event (TEAE; IR/ER HB/APAP, 25%; placebo, 7.9%). All TEAEs in IR/ER HB/APAP-treated patients were mild or moderate in severity.

Conclusion: IR/ER HB/APAP provided rapid, significant, and consistent analgesic efficacy over a period of 48 hours in an established model of acute pain and was tolerated with a safety profile similar to other low-dose opioids.