Long-Term Safety of Diet Drugs Unknown
Jan. 8, 2007 — Canadian researchers say there is still far too little
information about the long-term safety and effectiveness of three major weight
lossweight loss drugs.
The researchers say major questions remain about the long-term safety of the
obesityobesity drugs Meridia, Xenical, and Acomplia, and
they argue that very little research is being done to answer these
questions.
Meridia was approved by the FDA in 1997; Xenical won approval in 1999.
Acomplia, also known as rimonabant, has not yet been approved for sale in the
U.S., but it is available in Europe.
The three drugs act in very different ways. Meridia targets specific
chemicals in the brain to reduce appetite, while Xenical helps prevent the
absorption of fats from the foods users eat. Acomplia targets what is thought
to be the brain’s pleasure center to reduce food cravings.
Raj S. Padwal, MD, and Sumit R. Majumdar, MD, reviewed the research that has
been done on the three antiobesity drugs, and concluded that the clinical
trials have been limited by high drop-out rates among study participants and a
lack of long-term data on illness and death.
Their findings appear in the Jan. 6 issue of the journal The
Lancet.
“We have a good idea of how much weight loss to expect on average with
these medications,” Padwal tells WebMD. “But there is a lot we still
don’t know. If people are going to be put on these drugs long term we really
need to know if they are doing more net benefit than harm.”
Weight Loss Is Modest
Two-thirds of Americans are overweight or obese and one-third qualify as
obese, according to the CDC. Worldwide, the International Obesity Task Force
estimates that 1.1 billion people are overweight or obese.
“There is no other condition out there that affects so many people,”
he says. “That is why the search for effective treatments is so
important.”
In terms of promoting weight loss, none of the three drugs performed
significantly better than the others in the clinical trials, which lasted up to
four years. That weight loss could be characterized as modest, at best, Padwal
says.
Studies suggest that Xenical can help lower cholesterol and reduce diabetesdiabetes risk, but Padwal and Majumdar conclude
that it should probably be avoided by people with chronic diarrheadiarrhea.
Some studies have found a slight increase in blood pressure associated with
Meridia use, so the researchers conclude that it should not be prescribed to
people with poorly controlled high blood
pressurehigh blood pressure
“until further efficacy and safety data are available.”
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