Each year, millions of coughing, wheezing, phlegm-filled people flock to their doctor's office asking for antibiotics to treat lower-respiratory-tract infections. These infections, which include bronchitis, account for the majority of doctors' visits, 55 percent of all prescriptions, and nearly a billion dollars a year in healthcare costs in the United States and England combined. But in recent years, researchers have learned that the overuse of antibiotics can lead to problems including drug-resistant bacteria and the killing of healthy bacteria in the gut, not to mention money wasted when the antibiotics don't work. Because of doubt that these drugs are effective treatments for lower respiratory illness, British researchers looked into whether antibiotics actually helped patients recover from these infections.

What the researchers wanted to know: Do antibiotics help treat lower-respiratory-tract infections?

What they did: Researchers found 807 patients diagnosed with lower-respiratory-tract infections. The researchers then divided these patients into three groups: patients who received antibiotics immediately, patients who had the option to receive antibiotics later, and patients who didn't receive any antibiotics. Patients kept track of the duration and severity of their disease in a diary where they recorded their temperature, their use of pain relief/fever-reducing drugs (like aspirin or acetaminophen), and the severity of six symptoms: cough, difficulty breathing, mucus production, well-being, sleep disturbance, and activity disturbance.

What they found: There was no significant difference in the duration of coughing or the severity of the disease between those patients who took antibiotics, in either the immediate or delayed group, and those who didn't. However, patients who received antibiotics reported one less day of symptoms such as phlegm, sleep disturbance, activity disturbance, and generally feeling unwell than those who didn't receive antibiotics.

What this means to you: Although you might feel worse for a bit longer without antibiotics, these medications make little difference in how well you recover from the infection. In any case, the symptoms will most likely last about 22 days. Because lower-respiratory-tract infections like bronchitis can turn into pneumonia, a potentially dangerous disease, patients should consult their doctors if symptoms worsen.

Caveats: With the open design of this study (no patients took placebos), the authors say the patients taking antibiotics may have experienced a "placebo effect," which would lead them to think the drugs were helping them when in fact they had no effect. Also, researchers relied on the patients to report their own symptoms, whereas a clinician's examination might have given a more accurate picture of the disease's progress.

Find out more: The U.S. Food and Drug Administration and the Centers for Disease Control and Prevention both have online pages on the overuse of antibiotics. The American Academy of Family Physicians has a page on acute bronchitis.

Read the article: Little, P., et al. "Information Leaflet and Antibiotic Prescribing Strategies for Acute Lower Respiratory Tract Infection." Journal of the American Medical Association. June 22, 2005, Vol. 293, No. 5, pp. 3029–3035.

Read the abstract: http://jama.ama-assn.org