Patients with breast cancer undergoing mastectomy experience moderate postoperative pain which may persist for more than 3 months and may turn into chronic pain. This may interfere with the daily life of the patients. Proper prophylaxis and management to control postoperative pain are essential. Morphine is the most common drug to control postoperative pain. However, there are many serious side effects, e.g., nausea/vomiting, pruritus, ileus, constipation, sedation, and respiratory depression. Multimodal analgesia comprises the use of a combination of drugs to provide the opioid-sparing effect. Parecoxib, a selective cox-2 inhibitor, and intravenous paracetamol are reported to provide good postoperative analgesia. The investigators aim to apply a combination of parecoxib and paracetamol perioperatively to reduce postoperative morphine consumption.
