Drug also reduced contagious period and fever duration during H1N1 pandemic, researchers say
TUESDAY, Sept. 28 (HealthDay News) -- When taken shortly after the onset of symptoms, the antiviral drug Tamiflu seems to have protected otherwise healthy swine flu patients from contracting pneumonia during the 2009 H1N1 pandemic, Chinese researchers say.
Tamiflu may also have shortened the period that patients were contagious and reduced the duration of their fevers, the research team said.
However, reporting in the Sept. 29 issue of bmj.com, the study authors stressed that their findings should be interpreted with caution given that the conclusions are based on an after-the-fact analysis and on a pool of patients not uniformly given chest X-rays at the time of illness.
The study team, led by Dr. Weizhong Yang and Dr. Hongjie Yu from the Chinese Center for Disease Control and Prevention in Beijing, note that in 2009 the fast-spreading influenza A (H1N1) virus killed more than 18,000 people in over 200 countries.
Prior research has suggested that patients who take antiviral medications within two days of experiencing seasonal flu symptoms may develop a less severe and shorter-lasting illness and may also reduce their risk for complications.
To gauge to what degree this might be true for healthy patients with a mild form of H1N1, the research team reviewed the medical records of nearly 1,300 Chinese patients diagnosed with the infection in 2009.
The average age of the patients was 20. More than three-quarters were given Tamiflu within a median of three days following the onset of symptoms, and 920 of the patients underwent follow-up chest X-rays.
Just 12 percent of those X-rayed had signs of pneumonia, the researchers observed. None of them needed admission for intensive care, and none required mechanical ventilation.
Even after accounting for age, gender, influenza vaccine and antibiotic treatment history, the authors concluded that Tamiflu treatment appeared to offer significant protection against pneumonia.
This protective effect was apparent in all patients who took Tamiflu, even those who took it more than 48 hours after symptom onset, but those who took the medication within 48 hours experienced shorter fevers and were contagious for a shorter time.
The Chinese team nonetheless called for more follow-up research to investigate the potential benefits of Tamiflu for swine flu.
For more on swine flu, visit the U.S. Centers for Disease Control and Prevention.
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