Effectiveness and Safety of the Combination of Paracetamol 1000 mg and Ibuprofen 300 mg Versus Ibuprofen 600 mg in Monotherapy in Acute Low Back Pain: Results from a Phase IV Randomized Study

Objectives: This study aimed to evaluate the effectiveness and safety of paracetamol 1000 mg/ibuprofen 300 mg administered three times daily (TID) in comparison with ibuprofen 600 mg TID in the management of patients with acute moderate/severe non-specific low back pain (LBP). Methods: This was a phase IV, randomized, open-label, parallel-group study conducted in adults with moderate/severe LBP (Visual Analogue Scale [VAS] score ≥ 40 mm). Results: A total of 171 patients were included in the modified intention-to-treat (m-ITT) population (paracetamol 1000 mg/ibuprofen 300 mg: 83 patients; ibuprofen 600 mg: 88 patients). No significant between-group difference on the primary endpoint (SPID 0–3 days) was found. Patients were mainly women (60.2% and 55.7%), with a mean age of 42.8 and 43.3 years, respectively. In the m-ITT population, the effectiveness, safety and tolerability were similar between groups. In the per-protocol population, clinical pain reduction was observed with paracetamol 1000 mg/ibuprofen 300 mg. At visit 1, significant differences in the Clinical Global Impression–Improvement scale (paracetamol 1000 mg/ibuprofen 300 mg: 63.9%; ibuprofen 600 mg: 45.5%; p = 0.0137) and a trend favouring paracetamol 1000 mg/ibuprofen 300 mg in Patients’ Global Impression of Change (63.9% vs 44.4%; p = 0.0539) score were observed. Conclusions: Given the open-label design and the exploratory nature of study’s secondary endpoints, no claims of superiority can be drawn; but our findings confirm that good management of acute moderate/severe LBP can be achieved with multimodal therapy with paracetamol 1000 mg/ibuprofen 300 mg. EudraCT Number: 2020-005278-86 (EudraCT Number 2020-005278-86—Clinical trial results—EU Clinical Trials Register; date of registration: 14 June 2021).