RESUMO
OBJECTIVE: A comparative study of the effectiveness and safety of novel combination naproxen sodium and diphenhydramine in subjects with low back pain along with transient insomnia. MATERIAL AND METHODS: It was an open label, randomized, comparative, parallel group and multi-center clinical study. Subjects were randomised into one of three treatment arms: naproxen sodium 440 mg/diphenhydramine 50 mg, naproxen sodium 550 mg, Paracetamol 1000 mg/diphenhydramine 50 mg. All the subjects were advised to apply study drug ones before sleep for 3 days. All subjects also received naproxen sodium 275 mg as background therapy. The primary end-point was wake time after sleep onset (WASO) measured by actigraphy. Other secondary sleep and pain end-points were also assessed. RESULTS: Efficacy analysis was performed for intent-to-treat population (n=235 subjects). naproxen sodium 440 mg/diphenhydramine 50 mg combination showed significant improvements in WASO vs. naproxen sodium 550 mg (-42 min p=0.0174), while differences vs. Paracetamol 1000 mg/diphenhydramine 50 mg (-30 min, p=0.0891) were not significant. According to the average pain intensity difference in the lumbosacral spine combination product naproxen sodium 440 mg/diphenhydramine 50 mg was significantly improved compared with naproxen sodium 550 mg (-9.42, p<0.001) and Paracetamol 1000 mg/diphenhydramine 50 (-7.15, p<0.05). CONCLUSION: Naproxen sodium 440 mg/diphenhydramine 50 mg combination demonstrated improvement in sleep maintenance (WASO) vs. naproxen sodium 550 mg and higher efficiency in average daily pain reduction compared with the comparison groups. The treatment was well tolerated There were no serious or unexpected adverse events reported in the study.