Antibiotics are the most effective treatment for bacterial sinusitis. However antibiotics are ineffective against viral infections. In the early stages of a common cold caused by viral infection, you may ask your physician for antibiotics to “head off” an infection. There is no evidence to support this practice since antibiotics are ineffective against viral illnesses. It is estimated by the Centers for Disease Control and Prevention (CDC) that 1/3 of the 150 million outpatient prescriptions written for antibiotics in the United States each year are unnecessary. This overuse of antibiotics promotes the development of antibiotic resistant bacteria. Self treatment with antibiotics left over from a previous prescription or not completing a course of antibiotics as prescribed may create a chronic bacterial infection resistant to common antibiotics and interfere with the normal healing process.