ISLAMABAD: A combination of two common antibiotics may help delay symptoms of Alzheimer’s disease researchers said on Thursday.
In a 101-patient Canadian study, Alzheimer’s patients treated with antibiotics doxycycline and rifampin for three months had significantly less mental decline than those given dummy pills, said Dr. Mark Loeb, associate professor at McMaster University in Hamilton, Ontario, and the study’s lead author.
"The antibiotic regimen might allow a person suffering from Alzheimer’s disease to remain home and avoid having to go to a nursing home or other institution, at least for a period of time," said Dr. Loeb.
The Alzheimer’s Association, however, cautioned against generalizing the results from the relatively small study. "There is not enough data ... to recommend antibiotic treatment to physicians, patients and families," the association said in a statement.
Alzheimer’s is a progressive, degenerative disease that alters the brain, causing impaired memory, thinking and behavior. Health officials are bracing for a huge increase in Alzheimer’s as U.S. baby-boomers age. Currently more than 4.5 million Americans have the disease, which is always fatal and for which there is no cure.
The protective effect of the antibiotic regimen was similar to that of so-called cholinesterase inhibitors like Pfizer Inc.’s Aricept and Novartis AG’s Exelon, the only class of therapies currently approved for treating the degenerative brain disease, Loeb said. But only about half of Alzheimer’s sufferers respond to those drugs, according to the Alzheimer’s Association.
Loeb said there is a theory that a common bacteria that causes pneumonia might play a role in causing Alzheimer’s, but the antibiotics study found no evidence that levels of the bacteria were reduced as significantly as would be expected.
He suggested that the antibiotics may work by interfering with the buildup of plaques around neurons in the brain that are a hallmark of Alzheimer’s. It is also possible that the anti-inflammatory effects of the antibiotics are critical.
More work needs to be done to determine an exact mechanism of action. "We would like other people to replicate this study and look into the mechanism of action," Loeb said. He also warned that patients are at risk of becoming resistant to antibiotics given on a continual basis.
Nevertheless, Loeb suggested that antibiotics may be an option for Alzheimer’s patients who are not doing well on standard therapy.
"If I had a family member suffering from Alzheimer’s, I would show this study to the physician and see what they think," he said.
The trial found that mental scores of those in the placebo group declined by an average of 2.75 points more over six months than those who received the antibiotic, out of a 70-point scale. At 12 months, there was still a difference between the groups, but it was not considered significant.
Side effects including nausea and sleep disturbances were similar in both groups. Results from the trial of patients with mild-to-moderate Alzheimer’s were presented in San Diego at a meeting of the Infectious Diseases Society of America. | 
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