Premedication with controlled-release oxycodone does not improve management of postoperative pain after day-case gynaecological laparoscopic surgery

Abstract

Background. Controlled-release (CR) oxycodone provides an option for the prevention of postoperative pain. We designed this randomized double-blinded placebo controlled study to evaluate the control of pain after premedication with CR oxycodone 15 mg in addition to ibuprofen 800 mg orally in day-case gynaecological laparoscopic surgery. Methods. Sixty consenting patients were anaesthetized in a standardizedfashion. Postoperative analgesia was provided by ibuprofen 800 mg twice a day in combination with fentanyl i.v. in the recovery room and normal-release (NR) oxycodone orally after the recovery room. The visual analogue scale (VAS) scores for pain and side-effects, and the amounts of postoperative analgesics were recorded for 24 h after discharge from the hospital. After a statistical analysis of the original study, we extended the study to investigate another 10 patients, who received CR oxycodone 15 mg orally in an open-labelled fashion 60 min before surgery. The plasma concentrations of oxycodone were measured from samples drawn before and 2, 4, 6 and 8 h after premedication. Results. The amounts of fentanyl [100 μg (0-330) in the CR oxycodone group; 125 μg (0-330) in the placebo group], NR oxycodone, or the VAS scores for pain during the first 24 h after the discharge from the hospital did not differ after the premedication with CR oxycodone or placebo. In the extension study group, the peak plasma concentration (Cmax) of oxycodone was 10.0 (4.6-14.7) ng ml-1, indicating possibly a sub-therapeutic level. Conclusion. Oral premedication with CR oxycodone did not improve management of postoperative pain after day-case gynaecological laparoscopic surgery. © The Board of Management and Trustees of the British Journal of Anaesthesia 2007. All rights reserved.