The most essential difference between Clarithromycin extended-release tablets and Clarithromycin tablets is the difference in the dosage form. Clarithromycin tablets can be broken open and chewed. Clarithromycin extended-release tablets and clarithromycin tablets both belong to the macrolide class of antibiotics, and other drugs in its class include roxithromycin, azithromycin, erythromycin, etc.