Clarithromycin belongs to class of macrolide antibiotics. Clarithromycin is an antibiotic derived from erythromycin which is used in the treatment of certain bacterial infections, including lung infection, bronchitis, and ear infections, sinuses, skin infection and infection in the throat. Its antimicrobial activity prevents the growth of bacteria. The antibiotic is used in combination with other medications to prevent H. pylori, a bacterium that causes stomach ulcers. Clarithromycin comes as a tablet and also in as suspension (liquid) form to taken orally. Clarithromycin is consumed largely over the global and was the second most consumed drug in Canada in 2014.