Clinical efficacy of controlled-release oxycodone 20 mg administered on a 12-h dosing schedule on the management of postoperative pain after breast surgery for cancer.
OBJECTIVE
To assess clinical efficacy of controlled-release oxycodone (CRO) 20 mg on a 12-h dosing schedule in this prospective, randomised, placebo-controlled, double-blinded study of 40 ASA physical status I-III women undergoing breast surgery for cancer.


RESEARCH DESIGN AND METHODS
General anaesthesia using remifentanil and propofol was performed for surgery. Both groups received premedication with oral midazolam 7.5 mg 1 h before surgery. In the controlled-release oxycodone group, one tablet of 20 mg CRO was administered with the premedication, and 12 h after the premedication another 20 mg CRO. In the placebo (PL) group, a placebo tablet was administered with the premedication, and 12 h later another placebo tablet. All patients had access to opioid rescue medication via an IV patient-controlled analgesia (PCA) device.


MAIN OUTCOME MEASURES
Area under the curve (AUC), based on IV opioid rescue consumption over 24 h postoperatively.


RESULTS
The AUC for IV PCA opioid consumption was significantly lower in the CRO group than in the PL group (p = 0.01). The CRO group required less IV opioid loading dose (p < 0.001), and consumed less opioid rescue medication 4 h (p = 0.036), 16 h (p = 0.01), and 24 h (p = 0.005) postoperatively. AUC for VAS scores at rest was significantly lower in the CRO group than in the PL group (p = 0.05). VAS scores at rest were lower in the CRO group 16 h (p = 0.04) and 24 h (p = 0.03) postoperatively. There was no difference in AUC for pain scores on movement (p = 0.103) and for quality of analgesia (p = 0.139). There was no difference in nausea between groups (p = 0.34). Pruritus, arterial hypotension or hypertension, bradycardia, and tachycardia were not observed in either treatment group. None of the patients showed signs of confusion, agitation, or respiratory depression.


CONCLUSIONS
The administration of CRO 20 mg on a 12-h dosing schedule halves postoperative IV PCA opioid consumption. CRO 20mg is effective in preventing pain after breast surgery for cancer with only mild side-effects.