RESUMEN
BACKGROUND: NSAIDs and paracetamol are the cornerstones of pain treatment after day case surgery. However, NSAIDs have numerous contraindications and consequently are not suitable in up to 25% of patients. Metamizole is a non-opioid compound with a favourable gastro-intestinal and cardiovascular profile compared with NSAIDs. OBJECTIVES: The study aimed to assess if a combination of metamizole and paracetamol is noninferior to a combination of ibuprofen and paracetamol in treating pain at home after painful day case surgery. DESIGN: A double-blind randomised controlled trial. SETTING: Single centre. PATIENTS: Two hundred patients undergoing elective ambulatory haemorrhoid surgery, arthroscopic shoulder or knee surgery, or inguinal hernia repair. INTERVENTION: Patients were randomly allocated to receive either metamizole and paracetamol (nâ=â100) or ibuprofen and paracetamol (nâ=â100) orally for four days. MAIN OUTCOME MEASURES: Average postoperative pain intensity using a numerical rating scale and use of rescue medication were measured in the postanaesthesia care unit (PACU) and on postoperative days (POD) 1 to 3. A difference in mean numerical rating scale score of 1 point or less was considered noninferior. Adverse effects of study medication and satisfaction with study medication were measured on PODs 1 to 3 by telephone follow-up. RESULTS: In the PACU, the difference in meanâ±âSD pain score between metamizole and paracetamol and ibuprofen and paracetamol was 0.85â±â0.78. From POD 1 to 3, this difference was lower than 1, resulting in noninferiority. Rescue opioid consumption in the PACU and on PODs 1 and 3 was not significantly different between treatment groups. Rescue opioid consumption on POD2 was significantly higher in the ibuprofen and paracetamol group (Pâ=â0.042). Adverse effects of study medication and overall patient satisfaction were similar in both groups. CONCLUSION: Paracetamol/metamizole and paracetamol/ibuprofen are equally effective in treatment of acute postoperative pain at home after ambulatory surgery with comparable patient satisfaction levels. TRIAL REGISTRATION: European Union Clinical Trials Register 2015-003987-35.