LONDON – Three diet drugs recommended for long-term use result in minimal weight loss and carry some serious side effects, a review of research found. But experts say the drugs may still be worth it for some people.
Though most users of the prescription drugs remained overweight, the drugs improved cholesterol levels and blood pressure and reduced diabetes, the researchers reported in Friday's British Medical Journal.
"Drugs are not the magic cure and are not for everybody," said Dr. Raj Padwal, an assistant professor at the University of Alberta in Canada, one of the paper's authors. "But in specific patients, they have great benefits."
The researchers in Canada and Brazil analyzed existing data on three weight-loss drugs: Xenical, Meridia and Acomplia, which isn't sold in the United States.
Scientists found that patients on the drugs lost less than 11 pounds on average.The study participants — men and women between 45 and 50 years old who weighed about 220 pounds and had a body mass index of about 35 — used the drugs for periods of between one and four years.
Some experts say that the few pounds the drugs help people shed are worth it.
"Modest weight loss brings surprisingly big health gains," said Susan Jebb, head of nutrition and health at Britain's Medical Research Council. Jebb was not tied to the study.
"We are not just fighting obesity, but the things that come along with it," Jebb said.
Losing as little as 5 pounds can help reduce the risk of heart disease and diabetes, she said.
While the drugs are sold by prescription, other experts worry about giving people easier access to them.
"Selling anti-obesity drugs over the counter will perpetuate the myth that obesity can be fixed simply by popping a pill," wrote Dr. Gareth Williams, of the University of Bristol, in an editorial in the journal.
A lower-dose version of Xenical called Alli is sold over the counter in the U.S., and its maker, GlaxoSmithKline PLC, is seeking approval for sales in Europe.
Padwal and colleagues looked at 16 studies that tested Xenical. Also known as orlistat, Xenical works by preventing fat digestion. It helped people lose about 7 pounds on average. But it also reduced diabetes and improved cholesterol levels and blood pressure. Up to 30 percent of patients had unpleasant digestive and intestinal side effects.
In the 10 tests of Meridia, also known as sibutramine, study participants lost about 9 pounds on average and had improved cholesterol levels. Up to 20 percent had side effects including raised blood pressure and pulse rates, insomnia and nausea.
And in the four Acomplia studies, scientists found that users lost on average about 11 pounds. Acomplia, or rimonabant, also improved their blood pressure and cholesterol levels. The risk of mood disorders increased in 6 percent of patients.
Both Meridia and Acomplia work by interrupting nerve signals in the brain.
Another study published Friday in The Lancet also showed Acomplia raised the risk of psychiatric problems like depression and anxiety. Acomplia has been approved by the European Drug Agency, but was rejected by a U.S. Food and Drug Administration panel in June after it was told of the psychiatric side effects.
Padwal said the biggest caveat about the drugs is that their long-term effects are unknown. In 2005, global sales of the drugs were estimated at $1.2 billion.
Faced with an increasing global obesity epidemic — the World Health Organization estimates that 3 billion adults will be overweight or obese by 2015 — many experts think the drugs could be used more widely.
Jebb noted that diet and lifestyle changes haven't been very effective in fighting obesity.
"We've got to be realistic," she said. "Even though the weight losses from the drugs are modest, they're better than most other things we've got."