Clevudine is an antiviral drug for the treatment of hepatitis B. Target: HBV Clevudine is a nucleoside analog with an unnatural beta-L configuration. Clevudine showed potent antiviral activity during therapy and induced a sustained posttreatment antiviral effect for 6 months after a 12-week treatment period, and this was associated with a sustained normalization of ALT levels [1]. Clevudine showed a potent antiviral response, and its effect was higher in HBeAg-negative patients, with rapid viral load reduction after therapy. However, long-term therapy for more than 1 year resulted in the development of considerable resistance and myopathy. Therefore, we should consider alternative antiviral agents if clevudine resistance or clevudine-induced myopathy is developed in patients on clevudine for the treatment of CHB [2].