ors usually prescribe antibiotics for problems like pneumonia, but new research suggests that these drugs, especially penicillin, may also protect against strokes.
How could a drug that kills bacteria prevent a problem that involves the blockage of blood vessels supplying the brain? Strokes often occur when cholesterol plaques in blood vessels rupture and block blood flow to the brain. Interestingly, recent reports have shown that these plagues can contain bacteria. Some researchers believe that the presence of these bugs makes plaque rupture more likely.

This is where antibiotics come in. If an antibiotic can kill these bacteria, the plaque might become more stable and less likely to cause a stroke. To study the link between antibiotics and stroke, Dr. Paul Brassard, from Royal Victoria Hospital in Montreal, and colleagues compared antibiotic use between 1888 stroke patients and 9440 similar people who didn't experience a stroke.

People who used antibiotics within the previous year were about 20 percent less likely to have a stroke than people who didn't. Although several kinds of antibiotics seemed to lower the stroke risk, penicillins, such as amoxicillin and ampicillin, had the most pronounced effect.

Current penicillin users were 47 percent less likely to experience a stroke than non-users, the researchers note. Past penicillin use was also tied to a reduced stroke risk, but the benefit was not as strong as with current use.

Two or three studies are currently underway to see if antibiotics can prevent problems like stroke in heart attack patients, Dr. Brassard noted. If these go well, perhaps the stroke-preventing ability of antibiotics will be tested in people without any heart or blood vessel problems. Ultimately, we may one day see antibiotics prescribed to otherwise healthy people simply as means of preventing stroke, he added.