ICAAC: Statins also Battle Bacteria and Fungi

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ICAAC: Statins also Battle Bacteria and Fungi

MedPage Today - Little Falls,NJ*

By , Senior Staff Writer, MedPage Today

Reviewed by Zalman S. Agus, MD; Emeritus Professor at the University

of Pennsylvania School of Medicine.

September 21, 2007

http://www.medpagetoday.com/MeetingCoverage/ICAACMeeting/tb/6755

CHICAGO, Sept. 21 -- Statins, widely used for their anti-cholesterol

properties, also appear to have anti-microbial and anti-fungal

properties, researchers said here.

That finding may explain, in part, why some observational studies

have found that statin users are less susceptible to infections,

according to Jon Cohen, MBBS, of Brighton and Sussex Medical School

in Brighton, England. Action Points

Explain to interested patients that these studies suggest that -- in

vitro in the lab -- the drugs have an anti-microbial and anti-fungal

effect. But caution that the effect is small and not well understood.

These studies were published as abstracts and presented orally at a

conference. The data and conclusions should be considered to be

preliminary until published in a peer-reviewed journal.

The anti-bacterial effect -- seen so far only in the lab --

is " modest " and doesn't mean that statins can be used as

antibiotics, Dr. Cohen told attendees at the Interscience Conference

on Anti-microbial Agents and Chemotherapy.

But it may point the way to new antibiotics derived from the

statins, he said.

" If the chemists were to go away and play with the structure of

these drugs, they might be able to come up with new antibiotics, " he

said.

Akins, Ph.D., and colleagues at Wayne State University School

of Medicine in Detroit, also presented data on the topic, confirming

the British finding and extending it to fungi.

But Dr. Akins said he agrees with Dr, Cohen that, while commercial

statins are unlikely to be useful as antibiotics, they might be the

starting point for rational design of new medications that would

work better.

Researchers and physicians have known for several years that people

taking statins have an unexpected resistance to infection. Indeed,

at this meeting in 2001, a retrospective look at more than 9,000

patients showed that diabetic veterans taking statins had a 19%

reduction in the risk of lower extremity infections, compared with

those not on the drugs.

But that effect, also seen in other observational studies, could

have two explanations, Dr. Cohen said: The statins might be somehow

improving the immune response or they might be fighting pathogens

directly.

He and a colleague decided to test the second idea, using

simvastatin (Zocor) and fluvastatin (Lescol) against methicillin-

sensitive and --resistant Staphylococcus aureus and vancomycin-

sensitive and --resistant Enterococci.

Simvastatin showed a noticeable antimicrobial effect against

sensitive S. aureus with an average minimum inhibitory concentration

of 29.2 milligrams per liter. The drug also inhibited the resistant

bacteria, although more was needed, as well as vancomycin-resistant

enterococci.

Fluvastatin, on the other hand, had little effect, he said.

Dr. Akins and colleagues, testing a wider range of drugs and

bacteria, also found that " individual statins varied in the range of

species affected. "

For instance, he said, simvastatin, lovastatin (Mevacor), and

atorvastatin (Lipitor) all inhibited Bacillis subtilis, but none of

them inhibited Escherichia coli.

Dr. Akins and colleagues also reported that statins can inhibit a

range of Candida species, although the minimum inhibitory

concentrations are, again, so high that commercial drugs would not

be useful anti-fungal agents.

But the statins differ markedly in their ability to inhibit fungi,

which " suggests that rational, structure-based modifications to

current statins have the potential to dramatically increase their

antifungal activity, " Dr. Akins said.

On the other hand, Dr. Cohen said that the existing effect might be

enough to prevent an infection, even though it wouldn't be powerful

enough to cure disease.

" It could be that pre-existing statins (in the bloodstream) might

prevent an infection from catching on, " he said.

Both Dr. Akins and Dr. Cohen said more work is needed, especially to

tease out exactly how the inhibitor effect takes place.

The studies were conducted without outside funding. Dr. Akins and

Dr. Cohen reported they had no financial conflicts.