IV paracetamol 1 g is clinically equivalent to IV dipyrone 1 g for postoperative analgesia after surgery for breast cancer.

IV paracetamol 1 g has a similar analgesic potency as IV metamizol 1 g for postoperative analgesia after retinal surgery.

Aims: To assess clinical equivalence of 20 mg controlled-release oxycodone (Oxygesic®; Mundipharma, Limburg, Germany) and 200 mg controlled-release tramadol (Tramal long®; Grünenthal, Aachen, Germany) on a 12-hour dosing schedule in a randomized, double-blinded study of 54 ASA I–III physical status (American Society of Anesthesiologists classification of physical status) patients undergoing surgery for breast cancer. Methods: General anesthesia using remifentanil and propofol was performed for surgery. Patients were randomly allocated to 2 groups, receiving either 20 mg controlled-release oxycodone (Oxy group) or 200 mg controlled-release tramadol (Trama group) with the premedication (7.5 mg midazolam) and again 12 hours later. All patients had access to rescue medication (i.v. paracetamol). The primary variables for clinical equivalence were the differences between the mean values for pain scores at rest and pain scores on coughing over 24 hours after operation. The equivalence margin was determined as ±10 on the visual analogue scale. Results: Fifty-four patients were enrolled. Regarding pain scores at rest, the 90% CI of the mean differences between the treatment groups over 24 hours after operation was found to be within the predefined equivalence margin [–4.5 to +1.7], and the CI values for pain scores on coughing [–6.2 to +1.7] were similar. Cumulative paracetamol given over the 24-hour observation period did not differ significantly between the Oxy group (1.32 ±1.9 g) and the Trama group (1.61 ± 1.1 g; p = 0.32). There were no significant differences between the treatment groups regarding adverse events such as nausea (p = 0.13), vomiting (p = 0.24) and itching (p = 0.77). Also, no differences were found concerning patient satisfaction scores (p = 0.8) or patients’ general perception of postoperative pain management (p = 0.71). Conclusion: 20 mg controlled-release oxycodone is clinically equivalent to 200 mg controlled-release tramadol for postoperative analgesia after surgery for breast cancer.