Efficacy and safety of controlled-release oxycodone and standard therapies for postoperative pain after knee or hip replacement.

Background: Standard therapy (ST) for postoperative pain after knee and hip replacement at the Hamilton Health Sciences Henderson Hospital consists of epidural analgesia or patient-controlled analgesia for the first 48 hours, followed by oral or parenteral analgesics, or both, on an as-needed basis. We compared the efficacy and safety of scheduled controlled-release (CR) oxycodone hydrochloride (OxyContin; Purdue Pharma, Pickering, Ont.) and ST for postoperative pain 48 hours after primary knee and hip replacement.

Methods: In 2 separate 3-week studies of similar design, pain intensity, pain relief, length of hospital stay, analgesic use and side effects of CR oxycodone (n = 70) and ST (n = 101) were evaluated. In the CR oxycodone trial, a dose de-escalation protocol was used.

Results: At the time of discharge from hospital, patients in the CR oxycodone group recorded lower mean (and standard deviation) pain intensity scores than the ST group (20.2 [17.9] v. 27.7 [21.5] mm on a 100-mm visual analogue scale; p = 0.021). Length of hospital stay was 5.5 and 6.4 days for the CR oxycodone and ST groups respectively (p < 0.001). CR oxycodone patients used less opioid (morphine equivalent) while in hospital than ST patients (p < 0.001), and the average number of daily administrations of analgesics in hospital was 2.1 and 3.5 for CR oxycodone and ST patients respectively (p < 0.001). ST patients reported more nausea and vomiting, pruritus and fever than the CR oxycodone patients, but less somnolence, constipation, dizziness, confusion and tachycardia.

Conclusions: CR oxycodone every 12 hours is as effective as ST in treating postoperative pain but length of hospital stay was shorter and analgesic administration in the hospital was used less frequently, providing potential hospital cost savings and reduced use of health care resources.