Fixed Combination of Dipirone and Codeine Compared to the Isolated Use of Dipyrone and Codeine in Controlling Pain After Pelvic-abdominal Surgery.

Inclusion Criteria: * ≥ 18 years; * Patients in the 1st postoperative period of open abdominal or pelvic surgery (last 24 hours) and receiving short duration analgesics or opioids in any route of administration on the previous day, being able to receive oral medication and scheduled home discharge in hours or days, with pain moderate to intense intensity (defined as VAS pain ≥ 4); * Have signed the informed consent form. Exclusion Criteria: * Surgical complications to the inclusion of the participant in the research; * Other serious comorbidities at the discretion of the investigators (such as a history of renal, hepatic, cardiac or other peptic ulcer); * History of chronic and current use of opioids or other analgesics; * Users of alcohol or illicit drugs; * Use of drugs with the potential to interact with study drugs; * Allergy, hypersensitivity or known contraindication to the use of components of the study drug; * Psychiatric or social disorders that prevent adequate follow-up to the protocol; * Show inability to understand and perform current pain assessments in the study; * Women of childbearing potential, defined as all physiologically capable women of childbearing, unless they are using effective contraceptive methods while administering study medication; * Any clinical condition that the investigator considers to generate risk to the patient or interfere with the conduct of the study; * Participation in another clinical study in less than a year (unless participation by the principal investigator is justified).