MONDAY, Feb. 25 (HealthDay News) -- Almost half of nursing home patients with advanced dementia are given antibiotics in the last two weeks of life, a new study found.

What's not clear is whether or not that therapy has any benefits, such as prolonging life or improving the quality of life. And, of concern are the risks associated with antibiotic use, such as pain from intravenous antibiotics and unpleasant side effects, as well as the fact that frequent use of antibiotics in people with advanced dementia may help fuel the growing problem of antibiotic resistance.

"Antibiotic exposure is extensive in nursing home residents with advanced dementia, and it increases as patients near death," said study lead author Dr. Erika D'Agata, an assistant professor of medicine at Harvard Medical School. "We really need to determine if antibiotics should be given to patients at the end of life. Do they benefit from treatment?"

The study findings are published in the Feb. 25 issue of Archives of Internal Medicine.

About 70 percent of the 5 million Americans with dementia will end up in a nursing home at the end of their lives. Repeated infections and fevers are common at the end of life, according to background information in the study.

"In general, in the population of severely demented elderly patients, as the health of the patient deteriorates, infection becomes increasingly frequent. According to common medical practice, these episodes of infection are usually treated with antibiotics, but death often results nevertheless," the authors of an accompanying editorial in the journal, Dr. Mitchell Schwaber and Dr. Yehuda Carmeli, of the Tel Aviv Medical Center's division of epidemiology, said in an e-mail interview.

To get a more precise idea of how antibiotics are used in nursing home residents with advanced dementia, D'Agata and her colleague, Dr. Susan Mitchell, reviewed data from a group of 214 people and followed them for 18 months or until death.

The researchers found that 66 percent of the patients received at least one course of antibiotics during the study period, and that the average number of days an advanced dementia patient spent on antibiotics was 53 days per every 1,000 days. Respiratory-tract infections were the most common reason antibiotics were prescribed, according to the study.

During the study period, 99 people died. Of those, 42 percent were on antibiotic therapy during the last two weeks of their lives. Many were given antibiotics through an intravenous line or by intramuscular injection.

The next step, according to D'Agata, is to figure out whether these patients benefit from antibiotic therapy, and what are the consequences from the overuse of antibiotics to the patient and to society.

Dr. Gary Kennedy, director of geriatric psychiatry at Montefiore Medical Center in New York City, agreed that more research is needed. "Physicians need a bit more data on outcome than we have from this article. We can't say that we know what the consequences of withholding antibiotics in this group are. If the data says that most of the time treatment with antibiotics doesn't prolong life or improve quality of life, then physicians can go to the families with a recommendation not to treat someone in the advanced stages of dementia," he said.

Schwaber and Carmeli said: "Not every infection [in someone with advanced dementia] must be treated with antibiotics. If no enhancement in the quality of life can be expected by the use of antibiotics, withholding their use may be the appropriate step to take in the case of infection."

However, D'Agata, Kennedy, Schwaber and Carmeli all agreed that the decision to use antibiotics or not needs to be made on a case-by-case basis with the family. And, Kennedy added, this study points to the importance of having an advance directive, which allows patients to spell out their wishes for end-of-life care.

Soon after a diagnosis of dementia or Alzheimer's, patients and their families and treating physicians should discuss what types of treatment are wanted, Kennedy suggested. Would the person with dementia want to be placed on a ventilator or have a feeding tube? Would the person want to be hospitalized or medicated at the end of life?

"This needs to be done in early dementia, because the more the dementia progresses, the less they have the capacity to participate," Kennedy said.

More information

Learn more about end-of-life decisions for people with dementia at the Alzheimer's Association.