The drug Tamiflu may have protected young adults who caught the H1N1 swine flu virus in 2009 from developing pneumonia, a study in China has found.
Although the H1N1 swine flu pandemic is over, the virus has has joined the mix of seasonal influenza viruses and it is known to affect young adults and children more severely than seasonal flu, which kills more elderly people. The Chinese study found that early treatment with Tamiflu, known generically as oseltamivir, may have prevented young adults from developing full-blown pneumonia.
"We believe the absence of severely affected patients in our series is because of early admission to hospital and early treatment with oseltamivir for most patients," the researchers wrote in a paper in the British Medical Journal on Wednesday. Tamiflu, which comes as a pill made by Roche AG under license from Gilead Sciences, is the current drug of choice to fight flu.
However, there have been reports of cases of H1N1 swine flu being resistant to the effects of Tamiflu. GlaxoSmithKline makes an inhaled drug that works in a similar manner called Relenza, or zanamivir generically. The study, led by Hongjie Yu and Weizhong Yang at the Chinese Centre for Disease Control and Prevention, involved 1,291 patients in China who were confirmed with mild H1N1 infection during the 2009 pandemic.
Their average age was 20 years and 76 per cent of them were treated with oseltamivir from the third day of showing symptoms. Of 920 patients who had a chest X-ray, 12 per cent showed abnormal signs that indicated pneumonia. However, no one ended up in intensive care nor did they need mechanical ventilation.
After discounting factors such as age, sex, flu vaccination and antibiotic treatment, the researchers found that oseltamivir treatment was a significant protective factor against pneumonia. "This protective effect was seen in all patients including those who started treatment more than two days after onset of symptoms," they wrote.