Efficacy of combined treatment with S-carboxymethylcysteine (carbocisteine) and clarithromycin in chronic rhinosinusitis patients without nasal polyp or with small nasal polyp.

In Japan, fourteen-membered ring macrolides, antibacterial agents, and S-carboxymethylcysteine (SCMC; carbocisteine), a mucolytic, are commonly used to treat chronic rhinosinusitis (CRS), and they are also used in combination. However, no large-scale randomized study has examined the effects of these pharmacotherapies. The aim of this study is to evaluate the effect of combined administration of clarithromycin (CAM), a fourteen-membered ring macrolide, and SCMC, compared with CAM single therapy. Patients with CRS were centrally registered and randomly assigned to treatment with CAM (200mg/day) alone (monotherapy group) or CAM (200mg/day) in combination with SCMC (1500mg/day; combination group) for 12 weeks. We assessed the clinical efficacy of the treatments using measures of subjective symptoms and objective findings, health-related quality of life (HRQOL) determined by the 20-Item Sino-Nasal Outcome Test (SNOT-20) score and computed tomography (CT) score. Four hundred twenty-five subjects were enrolled (combination group, 213; monotherapy group, 212). At week 12 of treatment, the rate of effectiveness was significantly higher in the combination group (64.2%) compared with the monotherapy group (45.6%; P=0.001). In addition, objective findings, including characteristics of nasal discharge (P=0.008) and post-nasal discharge (P=0.002) were significantly improved in the combination group. In both groups, SNOT-20 and CT scores were significantly improved from week 0 (P<0.001), and were not significantly different between groups. The results indicated that long-term combination therapy with SCMC at a dose of 1500mg/day and CAM at a dose of 200mg/day is effective for improving subjective symptoms and objective findings in adult patients with CRS.