News in brief - March 6, 2006

Supplements give limited benefits - First of new antibiotic class gets FDA review - Metabolic differences in enzymes - Elderly at higher risk of death when spouse is hospitalized

Supplements give limited benefits

Flying in the face of conventional wisdom, a new study found that calcium and vitamin D supplements provide only a modest benefit in preserving bone mass and preventing hip fractures in healthy postmenopausal women. The supplements also were found to be ineffective at preventing other types of fractures or colorectal cancer and were associated with an increase in kidney stones.

The findings, which were published in the Feb. 16 New England Journal of Medicine, were the results of a large clinical trial that was part of the Women's Health Initiative and included more than 36,000 women ages 50 to 79.

Despite improvements in hip bone density, the reduction in hip fractures was less than expected, the researchers said.

But women who were most conscientious about taking the supplements experienced a 29% decrease in hip fractures, and women 60 and older had a 21% reduction in broken hips, the researchers noted.

A separate study of nearly 32,000 women also found no significant association between levels of physical activity and colon cancer. That study was published online Feb. 17 in the International Journal of Cancer, the journal of the International Union Against Cancer.

First of new antibiotic class gets FDA review

The Food and Drug Administration has begun analyzing data on retapamulin, the first in the pleuromutilins class of antibiotics, according to a February statement by GlaxoSmithKline.

The company submitted a new drug application in November 2005 for this topical antibiotic asking it to be approved for skin infections caused by Staphylococcus aureus and Streptococcus pyogenes. It's intended to be used twice daily for five days, and GSK expects approval later this year.

Infectious disease experts long have complained that far too few antibiotics are in development and, with many organisms developing resistance to those that are currently available, the result is that not enough new ones are coming down the pike to replace those that are no longer useful.

"Continued widespread use of antibiotics has promoted the spread of antibiotic resistance and has created an urgent need for antibacterial agents with no known cross resistance," the company wrote.

Trials have suggested that this drug has a low likelihood of engendering resistance.

Metabolic differences in enzymes

Evidence that major changes occur during human development in the types and levels of enzymes responsible for the disposition of drugs and environmental chemicals was presented Feb. 16 at the American Assn. for the Advancement of Science annual meeting in St. Louis.

These enzymes can inactivate drugs, activate them or do both, depending on the compound and the number of enzymes involved, researchers said. They noted that the application of this and similar information could help predict a child's likelihood of effective drug treatment or susceptibility to an unfavorable drug reaction.

"The dramatic changes observed in enzyme expression must be considered when examining issues of drug effectiveness and safety during early life stages," said lead investigator Ronald N. Hines, PhD, professor of pediatrics and pharmacology and toxicology at the Medical College of Wisconsin in Milwaukee.

"Additional studies are needed to understand how these dramatic changes are regulated and the molecular basis for differences among individuals, to better predict drug and toxicant responses in children," he said.

Elderly at higher risk of death when spouse is hospitalized

Those 65 and older who are married to someone who is admitted to the hospital are more likely to die within the next year than those who have a healthy spouse, but this varies by gender and the reason for the hospitalization, according to a study in the Feb. 16 New England Journal of Medicine.

Researchers analyzed the claims data of more than 500,000 seniors enrolled in Medicare in 1993 and followed them for nine years. Overall, a man's risk of dying if their spouse was severely ill was 22%. It was only 16% for women. Men had a 6% increased risk of death if their spouse had colon cancer; women's risk increased by 3%. Dementia in a spouse increased a woman's risk to 5%; a man's risk increased 9%.

The authors called for strategies to address issues that could come up for caregivers and that might cause this phenomenon.

"It seems clear that a person's illness or death can have health consequences for others in his or her social network," said Nicholas Christakis, MD, PhD, lead author and professor in the Dept. of Health Care Policy at Harvard Medical School in Boston. "Our work suggests that interventions might decrease the mortality of caregivers."