Cefdinir is an extended-spectrum, semisynthetic cephalosporin, which is taken orally. The medicine is effective against the most prevalent respiratory tract infections, such as Penicillin susceptible Streptococcus. pneumoniae, Moraxella catarrhalis, and Haemophilus influenza. Cefdinir treats bacterial infections such as Pneumonia, bronchitis (infection of the airway tubes that lead to the lungs) and infections of the skin, sinuses, tonsils, throat and ear. Cefdinir functions by killing bacteria.