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Aspirin, Acetaminophen May Prolong the Flu

Anti-fever drugs such as aspirin and acetaminophen may prolong symptoms of the flu, Baltimore researchers report.

In a review of several studies, flu sufferers who took one of the anti-fever medications were sick an average of 3.5 days longer than people who did not take either of the drugs. However, more study is needed to confirm the findings, because sicker patients were more likely to be given anti-fever drugs -- and may have been ill longer because they were more ill in the first place.

Some busy people would rather be somewhat sick for a longer time than be nearly wiped out for a shorter period, while some would rather stay sick longer but have relief from the aches and pains and fever that accompany the flu.

Researchers based the findings on several vaccine trials conducted in the 1970s and 1980s. In the studies, patients were injected with one of three disease-causing bacteria or viruses, including the type A influenza virus, which causes some cases of the flu.

Depending on their symptoms, some of the participants were given acetaminophen or aspirin, while others were not.

According to a report in the December issue of the journal Pharmacotherapy, the investigators found that anti-fever drugs prolonged the duration of the flu, but not of the other infections. On average, flu symptoms lasted 5.3 days in participants who did not take aspirin or acetaminophen, compared with 8.8 days in people who took the anti-fever drugs.

Since study participants who took anti-fever drugs tended to have higher maximum temperatures and more symptoms, the researchers considered the possibility that more severe cases of the flu caused symptoms to last longer. But in an analysis that took into account the severity of illness and other factors, the use of anti-fever drugs was still linked to longer-lasting illness.

Exactly why the drugs are linked to prolonged flu symptoms is unclear, the report indicates. One possibility is that reducing fever may interfere with the immune system's response to an infection, the authors note.

Similar findings have been reported in studies of chickenpox. In the studies, shedding of the chickenpox virus increased in children who were treated with anti-fever drugs.