It is important that you only use antibiotics for bacterial infections. Antibiotics help stop bacterial infections by acting on peptidoglycan, 70S ribosomes and bacterial enzymes. Viruses DO NOT HAVE THESE. Therefore, using an antibiotic for a viral infection will not stop your cold.
The other important reason NOT to take antibiotics for a viral infection is that those antibiotics will target and kill your normal flora/commensal organisms. Normal flora/commensal organisms keep you healthy. As a matter of fact, you are paying more for food (yogurt, drinks, infant formula, etc.) that promote the maintenance of normal gut flora ( probiotics are normal gut flora).
So, when you take antibiotics for an illness caused by viruses, you are actually having a harmful effect on your global health. Antibiotics can allow resistant organisms to expand and colonize your intestinal tract and you will be less healthy in the long run. Don’t take antibiotics for the wrong reasons.
So, let’s discuss the wrong reasons: Any disease caused by a virus. Most people don’t realize just how many of the most common illnesses actually are caused by viruses and not bacteria.
The majority of all common colds are caused by rhinoviruses or other viruses. There are over 100 strains of rhinovirus which means that you can have 100 infections and still never have had the same infection twice. From the CDC:
When germs that cause colds first infect the nose and sinuses, the nose makes clear mucus. This helps wash the germs from the nose and sinuses. After two or three days, the body’s immune cells fight back, changing the mucus to a white or yellow color. As the bacteria that live in the nose grow back, they may also be found in the mucus, which changes the mucus to a greenish color. This is normal and does not mean you or your child needs antibiotics.
Summer “flu” symptoms are caused by enteroviruses (not treatable with antibiotics ) which cause the following symptoms:
Infected persons who become ill usually develop either mild upper respiratory symptoms (a “summer cold”), a flu-like illness with fever and muscle aches, or an illness with rash. Less commonly, some persons have “aseptic” or viral meningitis.
Bronchitis is caused by viruses in the majority of all cases. These viruses are predominantly adenovirus, respiratory syncytial virus (RSV), or the flu (Influenza virus) and only RARELY by bacteria. Symptoms can last two to three weeks. Yes, I said symptoms can last for TWO to THREE WEEKS. According to the CDC:
Antibiotics will rarely be needed since acute bronchitis and bronchiolitis are almost always caused by a virus and chronic bronchitis requires other therapies.
When to use antibiotics: Only when you have a bacterial infection.
You should visit a doctor to determine if you have a bacterial or viral infection. But if the doctor does not give you antibiotic, it just means he is properly taking care of your global health and not just treating symptoms.