Inadequate control of acute postoperative pain (DAPO) brings deleterious consequences for the patient, including significant cardiovascular and respiratory complications. Apart from the human suffering that is undeniable pain. Schemes oral analgesia with opioids for the treatment of DAPO, have shown to be as or more effective than intravenous or epidural regimes, and less expensive. Comparing the effectiveness of 10 to 20 mgs of oxycodone sustained release for 12 hours before surgery, into two groups of 20 patients (O-10, O-20) undergoing orthopedic surgery, in a scheme involving multimodal ketoprofen, dipyrone metoclopramide and dexamethasone. Values were recorded visual analog scale (VAS)for pain at rest and effort, requirement for rescue intravenous morphine and incidence of side effects to the entry and exit of the PACU (T0, TE) and at 6 and 18 hours postoperatively (T6, T18),and patient satisfaction.