Clarithromycin (CAM) is 14-membered ring macrolide antibiotic that also acts as a biological reaction modifier with anti-inflammatory properties. In Japan, CAM is applied to diffuse panbronchiolitis, chronic bronchiolitis, otitis media, and chronic sinusitis as an immunomodulator [19] [20] [21] . The anti-inflammatory mechanism of CAM has not yet been completely clarified, but one of the important mechanisms for its anti-inflammatory action is considered to be the suppression of NF-κB [22] [23] [24] .