A large study found that people who were taking these drugs when they caught seasonal flu and had to be hospitalized were twice as likely to survive than those who were not on such medicines.
This doesn't prove that statins can cure flu, or that starting on them after catching the flu would help. A federal study is under way now to test that. Doctors are optimistic, because previous studies also found that statins may improve survival from infectious diseases.
"It's very promising," said the new study's leader, Dr. Ann Thomas of the Oregon Public Health Division. Results were discussed Thursday at an Infectious Diseases Society of America conference in Philadelphia.
"It's intriguing and exciting," and the benefit seen from statins is "substantial," said Dr. William Schaffner, a Vanderbilt University doctor whose hospital in Nashville, Tenn., was involved in the research.
"There are relatively few downsides to trying statins," which are cheap, relatively safe, and already among the most widely used medicines in the world, he said.
Treatment is a crucial issue for swine flu because vaccine is slow to reach the public, and flu medicines like Tamiflu are being reserved for only the sickest patients.
Statins have long been known to reduce inflammation along with cholesterol. Much of the damage that flu causes, whether it's seasonal or the new H1N1 virus, is from inflammation and an overreaction by the immune system as it fights the virus.
Earlier studies found that statins improved survival from pneumonia and serious bacterial bloodstream infections. The new research, sponsored by the federal Centers for Disease Control and Prevention, is the first large one in the United States to look at statins for flu.
It involved 2,800 people hospitalized with lab-confirmed seasonal flu in 10 states in 2007-2008. Medical records show that 801 received statins in the hospital. They probably were just continuing the cholesterol treatment they had been taking before catching the flu, though researchers don't know this for sure.
More than 3 percent of those not taking statins died in the hospital or in the following month. The rate was half that among statin users, even though they were more likely to have underlying health problems like heart disease. Researchers took other factors such as age into account and still saw the same benefit from statin use.
"It's an important study," said Dr. Andrew Pavia, a pediatrics professor at the University of Utah and head of the infectious disease society's pandemic flu task force. He said he now places a high priority on testing statins as a treatment.
"It gives us a pretty cost-effective tool if it works," he said.
There might be justification for trying these drugs now in certain patients not doing well on any other treatment, said Dr. Ronald Turner of the University of Virginia, a prominent virologist who had no role in the new study.
"If you get yourself to the point where you don't have anything to offer and things are going poorly for the patient, then maybe to try something on a speculative note is appropriate," he said.
The statin study is the second piece of good news on the treatment front in a week. Last Friday, the federal Food and Drug Administration authorized emergency use of the experimental drug peramivir as a swine flu treatment.
Recent results from an Asian study showed that a single intravenous dose of peramivir cleared up flu symptoms as effectively as five days of Tamiflu pills. Some very sick patients need IV treatments because they can't swallow pills or absorb the medicine well.
BioCryst Pharmaceuticals Inc. of Birmingham, Ala., is developing peramivir with Japan-based Shionogi & Co.
Statins are available in generic form and also sold as Lipitor by Pfizer Inc.; Zocor by Merck & Co.; Crestor by AstraZeneca PLC, and Pravachol by Bristol-Myers Squibb Co., among others.