New Study Shows Clinicians Under-Prescribing Flu Antiviral Drugs and Possibly Overprescribing Antibiotics

July 17, 2014 – A new study of flu treatment practices during the 2012-13 season found that clinicians under-prescribed flu antiviral drugs, such as oseltamivir (brand name “Tamiflu”) and zanamivir (brand name “Relenza”) among patients who sought health care for acute respiratory illness (ARI). Results showed that some groups recommended for flu antiviral treatment by CDC, such as young children, were particularly unlikely to be prescribed antiviral medications. In contrast, clinicians may have overprescribed common antibiotics. The authors of the study concluded that more needs to be done to educate clinicians on the benefits of flu antiviral drugs in high risk patients as well as the dangers of overprescribing antibiotics. Such practices have led to an alarming increase in bacterial drug resistance.

The study, published today in Clinical Infectious Diseases, collected data from five sites in the U.S. Flu Vaccine Effectiveness Network during the 2012-2013 flu season. Study participants included patients 6 months of age and older with ARI defined by cough for seven or less days. All patients were tested for flu infection using laboratory confirmation (via polymerase chain reaction).

Among patients with laboratory confirmed flu and for whom antibiotic data was available, results showed that 30% were prescribed one of three antibiotics, whereas only 16% were prescribed antivirals. Antibiotics are not recommended for treatment of viral infections because they do not benefit patients and can put them at harm for allergic reactions, antibiotic-resistant infections, and deadly diarrhea caused by the bacteria Clostridium difficile.

Antiviral treatment results showed that less than one-fifth (19%) of patients at high risk for flu complications who presented for care within two days of symptom onset (i.e., the period of time when antiviral treatment is most beneficial) received a prescription for antivirals. CDC recommends early antiviral treatment for people with suspected flu illness who are at higher risk for flu complications or who are severely ill. This includes hospitalized patients with suspected or confirmed influenza, those with severe or progressive illness, and outpatients who are at high risk for flu complications (for example, young children, people aged 65 years and older, pregnant women, and persons with certain underlying chronic medical conditions).

Observational studies from many countries have shown that early treatment of flu patients reduces the duration of hospitalization and the risk of severe outcomes, such as intensive care unit (ICU) admission or death. These studies have reported that clinical benefit of antiviral treatment is greatest when started within 48 hours of illness onset; however, clinical benefit has still been observed when antiviral treatment is started up to five days after illness onset.

The study is available online from the Clinical Infectious Diseases Journal webpage at Use of Influenza Antiviral Agents by Ambulatory Care Clinicians During the 2012–2013 Influenza Seasonexternal icon. A summary of CDC’s antiviral guidance is available online at