The Impact of Baseline Pain Intensity on the Analgesic Efficacy of Ibuprofen/Caffeine in Patients with Acute Postoperative Dental Pain: Post Hoc Subgroup Analysis of a Randomised Controlled Trial

INTRODUCTION: A fixed dose combination (FDC) of ibuprofen 400 mg and caffeine 100 mg has been shown to be more effective than ibuprofen 400 mg alone for the treatment of acute postoperative dental pain in a phase III randomised controlled trial. A post hoc subgroup analysis of the primary data from an active-/placebo-controlled, double-blind, single-centre, parallel-group study was conducted in patients with moderate or severe baseline pain. METHODS: After dental surgery, patients with moderate or severe pain, which was determined on a 4-point verbal rating scale (‘no pain’ to ‘severe pain’), received a single dose of ibuprofen 400 mg/caffeine 100 mg FDC, ibuprofen 400 mg, caffeine 100 mg or placebo. Pain relief (PAR) and pain intensity were assessed 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 6, 7 and 8 h after administration of study medication. The primary study endpoint was the time-weighted sum of PAR and pain intensity difference (PID) from pre-dose baseline, summed for all post-dose assessment times from 0 to 8 h (SPRID(0–8h)). RESULTS: There were 237 patients with moderate pain and 325 with severe pain at baseline. SPRID(0–8h) was significantly improved with the FDC versus ibuprofen, caffeine and placebo in the moderate and severe pain subgroups. Adjusted mean SPRID(0–8h) difference for the FDC versus ibuprofen was 18.19 (p < 0.0001) for patients with moderate pain and 7.70 (p = 0.0409) for patients with severe pain. With the exception of the 7-h measurement in patients with moderate pain, PID was significantly improved with the FDC versus ibuprofen at all measured time points from 0.5 to 8 h. In the severe pain subgroup, PID was significantly improved for the FDC versus ibuprofen from 0.5 to 3 h post-dose, but was not significantly different thereafter. CONCLUSION: The enhanced analgesic efficacy of ibuprofen/caffeine FDC versus ibuprofen is most pronounced in patients with moderate intensity pain at baseline, and also evident in patients with severe baseline pain. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01929031.