Antibiotics Don't Help Viral Infections

Posted on Tue., Mar. 25, 2008
Dr. Stephen Daniels

Patients with a cold or the flu often request antibiotics, even when their doctor says they have a virus infection, and antibiotics won't help.

In these cases, antibiotics may even be harmful, with side effects such yeast infections and diarrhea, allergic reactions that can be severe, and the gradual loss of antibiotic effectiveness.

Viruses cause many of the most common infections we experience: colds, flu, bronchitis, sinusitis, conjunctivitis (pink eye), pharyngitis (sore throat) and diarrhea. Antibiotics are usually a risky waste of money for all these diseases.

Doctors who give in to patient requests and prescribe antibiotics for viral infections can receive lower rankings from HMOs, because giving antibiotics for viral illnesses is considered bad medical practice.

When patients hear I don't plan to prescribe antibiotics for their cold, they often respond with a suspicious frown. Many think that I would give them an antibiotic prescription if I really cared about them.

Some suspect that the HMO is pressuring me to not prescribe antibiotics to save money. Neither is true.

Another statement I hear commonly is: "Doc, I never get sick like this. This isn't just a cold; it's something more serious. It's so severe and gone on for so long. I know I need antibiotics."

I believe that their illness is likely much more severe than any recent cold or flu they've experienced, but it's still a viral illness. And antibiotics are unlikely to help.

Perhaps the person's effective immune response to past cold viruses has made his or her recent colds mild, but the cold viruses have gradually changed over five-to-10 years, and are now presenting the patient with a virus for which she or he has no or little immunity.

In fact, people with less serious viral illnesses often feel worse than those with more serious ones. A sore throat from a cold often hurts more than a "strep throat." And a person with stomach pain caused by a virus infection often feels worse than the person with appendicitis, at least at first.

The person with a cold can feel miserable: fatigued, runny nose, head and body ache, sore throat, cough, often with yellow or green phlegm. The person with the strep throat often has just one complaint, a sore throat. No cough, no headache, no runny nose, no body ache.

The cold requires rest and fluids. A strep throat needs antibiotic treatment.

Similarly, the person with appendicitis may have just a vague, increasing pain in the lower right abdomen. By contrast, the person with a viral intestinal infection often feels miserable: diarrhea, cramping, fever, headache, vomiting and body ache.

The viral intestinal infection generally just needs fluids and rest. Appendicitis usually requires urgent surgery.

The treatment of "bronchitis" is different. The term "bronchitis" is a medical term for a cough. In general, antibiotics won't help bronchitis, even if the phlegm is yellow or green.

But, patients with asthma, chronic obstructive pulmonary disease (COPD), and emphysema may get some benefit from antibiotics if they are coughing and short of breath.

So, don't make up your mind ahead of time about the right treatment for your illness. Tell your doctor the details, and let him or her decide. It's always appropriate to ask for an explanation, though.

Daniels practices family medicine at the Concord, Martinez and Pittsburg Health Centers which are part of the Contra Costa Health Services.