|Short description Overview Amoxicillin is a penicillin antibiotic. It is prescribe to treat bacterial infections such as bronchitis, tonsillitis, gonorrhea, pneumonia and infections of the ear, nose throat, urinary tract and skin. The medicine can also be used with clarithromycin (Biaxin) to treat certain stomach ulcers that are caused by Helicobacter pylori infections. This combination can also be used with lasoprazole (Prevacid).   There are many brands of Amoxicillin available.