Methadone patient-controlled analgesia for postoperative pain: a randomized, controlled, double-blind study

Postoperative pain is an important health-care issue. Patient-controlled analgesia (PCA) is considered the gold standard for systemic postoperative pain treatment. Methadone PCA is used for patients with chronic pain and those in the palliative care setting. However, its efficacy as a first-line drug for acute postoperative pain is unknown. This study evaluated the use of postoperative methadone PCA after total hip arthroplasty (THA) compared with morphine PCA.

This was a randomized, double-blind, controlled, parallel-group study. Patients were randomized into two groups: group methadone--methadone PCA, and group morphine--morphine PCA, for postoperative analgesia. Drugs were delivered through PCA pumps throughout the first 24 h after surgery (T1:6, T2:12, T3:18, T4:24 h).

Opioid consumption in 24 h was significantly lower for group methadone than for group morphine. Group methadone patients experienced significantly less pain than group morphine at rest. Pain after movement was significantly lower in group methadone at T1 and T3 and marginally lower at T2 and T4. Adverse events more frequently reported were sleepiness, nausea, and vomiting, but no statistical difference between groups was found.

This study demonstrated that methadone PCA prompted less opioid consumption and lower pain scores at rest and at motion in comparison with morphine PCA as postoperative analgesia after THA.