Clarithromycin

Clarithromycin is a macrolide antimicrobial agent that is the main component of proton pump inhibitor (PPI) triple Helicobacter pylori (H. pylori) eradication therapy. Moreover, clarithromycin resistance is the most critical component to determine either the success or the failure of the eradication. Recently, clarithromycin resistance has rapidly increased. Clarithromycin resistance mechanisms mostly depend on 23S rRNA gene mutations, and A2143G point mutation is the most critical. Thus, the pretreatment determination of clarithromycin susceptibility can guarantee eradication success. Moreover, genetic epidemiologic investigations on resistance-inducing mutations contributed to the development of molecular diagnostic tests for rapid decision for clarithromycin susceptibility. Meanwhile, further research is needed to identify the unknown mechanism of clarithromycin resistance.