Background: We have evaluated whether co-administration of intravenous (i.v.) paracetamol could enhance the analgesic efficacy of ketoprofen (a non-steroidal anti-inflammatory drug or NSAID) in patients undergoing a tonsillectomy.
Methods: This prospective, randomized, double-blinded and placebo-controlled add-on study with three parallel groups included 114 patients, aged 16-50 years, and scheduled for elective tonsillectomy. All patients were given ketoprofen 1 mg/kg i.v. after surgery, followed 5 min later by paracetamol 1 or 2 g i.v., or normal saline as a placebo. The primary outcome measure was the proportion of patients requiring oxycodone for rescue analgesia over the first 6 h (pain score >30/100 mm at rest or >50/100 mm during swallowing) after surgery.
Results: No difference was detected in the proportion of patients receiving oxycodone (31/37 in the paracetamol 1 g group, 29/39 in the paracetamol 2 g group and 30/38 in the ketoprofen-alone group) between the three groups. However, significantly less doses of rescue analgesia were provided in the paracetamol groups than in the ketoprofen-alone group (P=0.005); among those who required rescue analgesia, 27% less oxycodone was required in the paracetamol 1 g group (80 doses, P=0.023) and 38% less in the paracetamol 2 g group (64 doses, P=0.002) than in the ketoprofen-alone group (106 doses).
Conclusion: Combining paracetamol i.v. with ketoprofen at the end of tonsillectomy did not reduce the proportion of the patients requiring rescue analgesia, but the number of opioid doses was less in the add-on groups.