The weight-loss drug Meridia has been taken off the market by its manufacturer following the results of a study that linked the drug with an increased risk of heart attack and stroke. Abbott Laboratories is voluntarily withdrawing Meridia after a request from the U.S. Food and Drug Administration.

The FDA approved Meridia in 1997.

The new study, which involved about 10,000 obese and overweight men and women, found patients taking Meridia, generically known as sibutramine, had a 16 percent increased risk of serious cardiovascular events compared with those taking a placebo.

There was only a small difference between the two groups in terms of how much weight they lost. People who took the drug lost about 2.5 percent more of their body weight, on average, than the those who took the placebo.

"I've never been enthusiastic about sibutramine," said Dr. Pieter Cohen, an assistant professor of medicine at Harvard Medical School and a general internist at Cambridge Health Alliance, who researches adverse effects of dietary supplements. Cohen said he sees a lot of obese and overweight patients, but prescribed the drug only once in the last decade.

"The reason is, all we knew about sibutramine was that it caused a modest amount of weight loss in the early trials that were used for FDA approval. But what we didn't know was whether or not that weight loss led to improved health of the people who were taking it," he said.

"Unfortunately it took 13 years since the time sibutramine was first approved, but now we see, 13 years later and after millions and millions of prescriptions have been written for it, is that it doesn't confer those health benefits," and also increases the risk of heart attack and stroke, he said.

The new study was carried out between January 2003 and March 2009 in Europe, Latin America and Australia.

"Meridia's continued availability is not justified when you compare the very modest weight loss that people achieve on this drug to their risk of heart attack or stroke," Dr. John Jenkins, director of the Office of New Drugs in the FDA's Center for Drug Evaluation and Research, said in a statement. "Physicians are advised to stop prescribing Meridia to their patients and patients should stop taking this medication. Patients should talk to their health care provider about alternative weight loss and weight loss maintenance programs."

Meridia was approved by the FDA for weight loss in obese individuals (those with a body mass index, or BMI, greater than or equal to 30). Overweight individuals (who have a BMI greater than or equal to 27) could also be prescribed the drug, if they had other risks for heart disease. BMI is calculated based on a person's height and weight, and is considered an indicator of body fatness.

The drug was approved after previous studies, lasting a year or less, found about 60 percent of those on the drug were able to lose at least 5 percent of their body weight, while only 30 percent of people taking a placebo were able to lose this much weight.

This isn't the first indication that Meridia poses heart risks. When the drug was originally approved, it was observed that it caused increases in blood pressure and heart rate, according to the FDA. However, the benefits of the drug were judged to outweigh the risks at lower doses.

In 2004, the drug's labeling was changed to note the blood pressure and heart rate concerns, and caution physicians against prescribing the drug to those with a history of heart disease and stroke, the FDA said.