Trenton, N.J. ? For the first time, it appears that more than half of all insured Americans are taking prescription medicines regularly for chronic health problems, a study shows.

The most widely used drugs are those to lower high blood pressure and cholesterol – problems often linked to heart disease, obesity and diabetes.

The numbers were gathered last year by Medco Health Solutions Inc., which manages prescription benefits for about one in five Americans.

Experts say the data reflect not just worsening public health but better medicines for chronic conditions and more aggressive treatment by doctors. For example, more people are now taking blood pressure and cholesterol-lowering medicines because they need them, said Dr. Daniel W. Jones, president of the American Heart Association.

In addition, there is the pharmaceutical industry’s relentless advertising. With those factors unlikely to change, doctors say the proportion of Americans on chronic medications can only grow.

“Unless we do things to change the way we’re managing health in this country … things will get worse instead of getting better,” predicted Jones, a heart specialist and dean of the University of Mississippi’s medical school.

Americans buy much more medicine per person than any other country. But it was unclear how their prescriptions compare with those of insured people elsewhere. Comparable data were not available for Europe, for instance.

Medco’s data show that last year, 51 percent of American children and adults were taking one or more prescription drugs for a chronic condition, up from 50 percent the previous four years and 47 percent in 2001. Most of the drugs are taken daily, although some are needed less often.

The company examined prescription records from 2001 to 2007 of a representative sample of 2.5 million customers, from newborns to the elderly.

Medication use for chronic problems was seen in all demographic groups:

¢ Almost two-thirds of women 20 and older.

¢ 52 percent of adult men.

¢ One in four children and teenagers.

¢ Three out of four people 65 or older.

Among seniors, 28 percent of women and nearly 22 percent of men take five or more medicines regularly.

Dr. Robert Epstein, chief medical officer at Franklin Lakes, N.J.-based Medco, said he sees both bad news and good in the findings.

“Honestly, a lot of it is related to obesity,” he said. “We’ve become a couch potato culture (and) it’s a lot easier to pop a pill” than to exercise regularly or diet.

On the good side, he said, researchers have turned what used to be fatal diseases into chronic ones, including AIDS, some cancers, hemophilia and sickle-cell disease.

Yet Epstein noted the biggest jump in use of chronic medications was in the 20- to 44-year-old age group – adults in the prime of life – where it rose 20 percent over the six years. That was mainly due to more use of drugs for depression, diabetes, asthma, attention-deficit disorder and seizures.