If you have a sinus infection, an antibiotic may be prescribed. No medicine exists that will kill or stop the growth of the viruses that cause the common cold. The only way to rid yourself of a common cold is to allow your body to get rid of the virus in its own way by getting plenty of rest. Generally your cold will be gone in 5 to 7 days. Some studies indicate that vitamin C 1000 mg.
Antibiotics have no effect on viruses.
Your body contains both harmful and helpful bacteria. The helpful bacteria keep harmful organisms under control. And can be affected by antibiotics permitting other illnesses or side effects to occur. Bacteria become resistant to antibiotics after they have been exposed to them often enough. After repeated courses of antibiotic therapy, bacteria may successfully change their structure so that they will be less affected by the antibiotic.