Analgesic and adverse effects of a fixed-ratio morphine-oxycodone combination (MoxDuo) in the treatment of postoperative pain.

OBJECTIVE

To compare efficacy and safety profiles of an immediate-release morphine and oxycodone Dual-Opioid combination (MoxDuo) versus its individual components and versus its morphine-equivalent doses in moderate to severe postoperative pain patients.

DESIGN

Randomized, double-blind, 48-hour, parallel-treatment, multicenter, six-arm study of MoxDuo.

SETTING

Six US centers.

PATIENTS

Within 6 hours after bunionectomy surgery, patients were eligible if they reported pain intensity > or = 2 on the 4-point Likert scale and > or = 4 on an 11-point Numerical Pain Rating Scale (197 randomly assigned; 175 completers).

INTERVENTIONS

MoxDuo 12 mg/8 mg, MoxDuo 6 mg/4 mg, morphine 12 mg, oxycodone 8 mg, morphine 6 mg, or oxycodone 4 mg (all administered q6h).

MAIN OUTCOME MEASURE

Sum of pain intensity differences 0-24 hours after the first dose of study medication (SPID24) and percentage of patients with moderate to severe nausea, emesis, or dizziness.

RESULTS

SPID24 was significantly better in the MoxDuo 12 mg/8 mg group when compared with its individual components (morphine 12 mg [p = 0.009] and oxycodone 8 mg [p = 0.037]), and when compared with MoxDuo 6 mg/4 mg (p = 0.011; 54.3 vs 28.5, 35.7, and 30.0, respectively). MoxDuo6 mg/4 mg and its morphine-equivalent doses (morphine 12 mg and oxycodone 8 mg) had comparable analgesic effects. There was a 50-75 percent reduction in moderate to severe adverse events (AEs) commonly associated with opioids (ie, nausea, vomiting, and dizziness) in the MoxDuo 6 mg/4 mg group when compared with its morphine-equivalent dose groups.

CONCLUSIONS

MoxDuo produced superior analgesic effects when compared with its individual components, but comparable efficacy when compared with its morphine-equivalent doses. Common AEs were reduced at least 50 percent with MoxDuo when compared with its morphine-equivalent doses. MoxDuo may be an improved intervention in the management of moderate to severe acute pain.