When the diet pill rimonabant was approved in Europe in 2007, it was hailed as a wonder drug for helping people lose weight, improve their cholesterol and blood glucose levels, among other things.
But after a major trial linked the drug to a slightly higher suicide rate, European officials shut it down and pulled the drug from the market. It was never licensed in the United States, but was sold as Acomplia, Riobant, Slimona, as well as under other names in Europe.
The drug targets certain brain receptors connected to processes including appetite and mood.
In a new paper, investigators say the trial was stopped too soon and that regulatory authorities became skittish after the suicides. The study was published Friday in the medical journal Lancet and was paid for by the drug's maker, Sanofi Aventis SA.
The trial wasn't testing the drug's weight loss benefits, but whether it might prevent heart problems. It was supposed to follow more than 18,000 patients in 42 countries for three years. Roughly half were given rimonabant while the other half were given a placebo.
After about a year, four people on rimonabant had killed themselves, versus one person in the placebo group. There were also nine attempted suicides in people on rimonabant, compared with five among those on placebo. At that point, the study was halted and the European Medicines Agency yanked its approval for the drug.
"Obviously the suicides are tragedies," said Eric Topol, director of Scripps Translational Science Institute and the study's lead author. "But we accept trade-offs in medicine and the psychiatric side effects might have been acceptable if we had found greater cardiovascular benefits later," he said.
He said rimonabant might still have been useful for fighting obesity, and that measures like stomach stapling surgeries also come with significant risk.
Other experts disagreed.
"Any mortality associated with cardiovascular preventive therapy is generally viewed as unacceptable," wrote Matthijs Boekholdt and Ron Peters of the department of cardiology in the Academic Medical Center in Amsterdam, in an accompanying commentary.
They argued that, even if rimonabant had not been marketed as a diet drug, the public would probably have seen it as "a miracle drug," and people would have taken it without being properly monitored for its dangerous side effects.