Antibiotics fight infections that are caused by bacteria, but they do not treat infections that are caused by a virus. Colds and flu are caused by viruses. If you have a viral infection, antibiotics will NOT make you better.
Antibiotics can destroy normal ("healthy") bacteria that live in your body. When this happens, symptoms such as nausea and diarrhea may develop, and women can get vaginal yeast infections.
The overuse of antibiotics has played a role in the increase of drug-resistant bacterial infections. Taking antibiotics can also put you at risk of an allergic reaction. Antibiotics should not be taken when they will not treat an illness.
Lindell A, Kelsberg G, Safranek S. Antibiotics for viral upper respiratory tract infections in children. Am Fam Physician. 2011;83(6):747-52. PMID: 21404988 www.ncbi.nlm.nih.gov/pubmed/21404988.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.