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A New 'Wonder' Drug for Weight Loss?
Study Shows Losing Pounds and Inches Is Easier
With Experimental Diet Drug
By
Peggy Peck
Reviewed By Brunilda Nazario, MD
on Monday, August 30, 2004
WebMD Medical News
Aug.
30, 2004 (Munich) -- An experimental diet drug
continues to show promise in the battle against
obesity, and may benefit those with multiple risk
factors for health-related complications stemming
from obesity.
In
the latest study of the drug rimonabant, overweight
volunteers who took 20 milligrams of the drug
daily for a year lost an average of 20 pounds
and reduced their waist size by an average of
over 3 inches.
Rimonabant
works by inhibiting the CB1 receptor, which works
on a newly described network system called the
endocannabinoid system (EC System). This system
plays a critical role in the regulation of food
intake and metabolism.
This
is the same drug that has shown promise as a smoking-cessation
aid, helping smokers quit smoking, while losing
rather than gaining weight.
The
newest study, which was presented at the European
Society of Cardiology meeting, reports on 1,500
overweight volunteers who were randomized to one
year of either 20 milligrams or 5 milligrams of
rimonabant or to a dummy pill.
All
of the volunteers had a BMI (a indirect measure
of body fat) of 27 or higher, which would classify
them as overweight or obese. They also had at
least one risk factor for obesity related complications
such as high cholesterol or high blood pressure.
In
addition, all the volunteers were told to reduce
their daily calorie intake by 600. This may explain
why even persons taking dummy pills lost an average
of 8 pounds, says researcher, Luc Van Gaal, MD,
a professor of medicine at Antwerp University.
In the study, those who took the low-dose rimonabant
lost an average of 10.5 pounds.
The
drug works by blocking endocannabinoid receptors,
which are found in the brain and in fat tissue.
These receptors play a role in cravings, so the
drug appears to work by turning off the "urge"
center in the brain. It "breaks the vicious
circle by cutting the desire to eat," Van
Gaal tells WebMD.
Seventy
percent of people taking 20 milligrams a day of
rimonabant lost more than 5% of their initial
body weight, compared with 44% of those taking
5 milligrams of rimonabant daily. Only 31% in
those taking the dummy pill lost 5% of their weight.
Drug
Helps 'Good' HDL Cholesterol
Van
Gaal says that an unexpected result of rimonabant
treatment was a 27% increase in HDL -- "good"
cholesterol -- among those taking the higher dose
of the drug. One of the most reliable ways to
increase HDL is through exercise but Van Gaal
says that increase seen in people taking rimonabant
was better than the HDL increase associated with
physical training.
However,
patients in the placebo arm also had a 10% increase
in HDL. Van Gaal says the increase is most likely
attributable to the decreased-calorie diet "but
the extra 10% in the rimonabant arm appears to
be a drug effect."
The
drug was well tolerated, although 13% of those
taking higher doses of the drug experienced gastrointestinal
symptoms including nausea and diarrhea, he says.
While
the rimonabant results continue to be positive,
not everyone is pleased to see a new diet drug.
Asked about the rimonabant in obesity treatment
studies, Richard Horton, MD, editor of The Lancet,
tells WebMD that he has reservations about the
use of a drug to treat obesity. "This isn't
rheumatoid arthritis and the idea of giving a
drug to people for years to treat obesity is troublesome,"
says Horton. "Moreover, we don't really know
if the weight loss in this study will translate
into reduced risk of cardiovascular disease."
Horton
was not involved in the study.
Van
Gaal says that Sanofi-Aventis, the maker of the
drug, plans to file for FDA approval during the
second quarter of 2005. He says the company will
probably ask the FDA to approve the drug for both
weight loss and smoking cessation.
--------------------------------------------------------------------------------
SOURCES:
European Society of Cardiology, Munich, Germany,
Aug. 28-Sept. 1, 2004. Hotline Prevention and
Medical Treatment I Session "RIO-EUROPE:
a randomized double-blind study of weight reducing
effect and safety of rimonabant in obese patients
with or without comorbidities. Luc Van Gaal, MD,
professor of medicine, Antwerp University, Antwerp,
Belguim. Richard Horton, MD, editor, The Lancet,
London, presented Aug. 29, 2004.
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