The increased risk was seen only in patients with underlying heart disease. When the FDA learned of the study results last January, Meridia use was restricted to patients without known heart problems.
The European regulatory authorities went further. They banned the drug, known generically as sibutramine and in Europe as Reductil.
Later this month, an FDA expert advisory panel will meet to decide whether Meridia should remain on sale in the U.S.
The researchers reporting the study, W. Philip T. James, MD, DSc, of the London School of Hygiene and Tropical Medicine, and colleagues, including researchers from Abbott, say the drug should stay on the market as long as it isn't sold to people with heart conditions.
The editors of the New England Journal of Medicine disagree. In a strongly worded editorial, they call Meridia "another flawed diet pill." They note that in return for offering a weight loss of under 9 pounds -- less than 5% of the body weight of the overweight participants in the study -- the drug had a one-in-70 chance of causing a heart attack or stroke.
People with underlying heart problems had an even higher one-in-52 risk of heart attack or stroke. And the New England Journal of Medicine editors note that many people who are overweight or obese have undiagnosed heart problems.
Since "the modest weight loss with [Meridia] did not translate into clinical benefit," the editors say, "it is difficult to discern a credible rationale for keeping this medication on the market."
James and colleagues find that among 10,744 overweight or obese people with heart problems or type 2 diabetes, 4.1% of those taking Meridia and 3.2% of those on placebo had nonfatal heart attacks. The nonfatal stroke rate was 2.6% in the Meridia group and 1.9% in the placebo group.
Importantly, they suggest, Meridia did not increase the overall death risk or the risk of death from heart disease and stroke.
Meridia "should continue to be excluded from use in patients with pre-existing cardiovascular disease," James and colleagues conclude.
The FDA panel will make its recommendations on Sept. 15.
The James study and the editorial appear in the Sept. 2 issue of the New England Journal of Medicine.