Ceftin Active ingredient: cefuroxime $1.79 for pill Ceftin is used for treating bacterial infections (sinus, skin, lung, urinary tract, ear, and throat). It may also be used to treat Lyme disease and gonorrhea. Omnicef Active ingredient: cefdinir $3.15 for pill Omnicef is used to treat many different types of infections caused by bacteria, such as acute flare-ups of chronic bronchitis, middle ear infections, throat and tonsil infections, pneumonia, sinus infections and skin infections.