| So
there are some drawbacks to each of these weight loss drugs.
They're also vulnerable to the abilities of our bodies' powerful
weight control mechanisms to fight back and regain the pounds
that have been shed.
And
that's the sum of what's on the market now. But researchers
are working overtime to come up with new drugs to help fight
obesity — and to tap into that massive potential market.
After all, almost two thirds of the adult population in the
U.S. is overweight or obese. That's well over 100 million
people who need to lose weight.
What
Might the Future Hold?
A
lipase-inhibiting drug similar to Xenical is in development
in the U.K. by the company Alizyme. Called ATL-962, the compound
targets the same lipase receptors in the gut and leads to
similar weight loss as Xenical. But Alizyme's CEO Richard
Palmer says that ATL-962 has one distinct advantage over its
already-approved rival. "What I refer to as our 'dry-cleaning
bill' side effect is about 90% reduced compared to Xenical,"
Dr. Palmer delicately puts it. "The fat is excreted in just
the same way. We don't have a definite molecular explanation
for the difference, but the fat left behind after Xenical
is present in little droplets that seem to coalesce into an
oil and cause problems. The ATL-962 ones do not appear to
coalesce." The company plans to submit drug data to the FDA
soon, and if all goes well, ATL-962 could be on the market
by 2008.
Pharmaceutical
companies are targeting a variety of different weight-regulating
systems as they try to create anti-obesity drugs. One promising
line of research focuses on peptide YY3-36, called PYY for
short. It's a hormone that's released by the small intestine
once you start eating. It tells your brain when you are full,
letting you know it's time to put down your fork. Since obese
people have less PYY in their blood than thinner people, it's
a tantalizing hope that administering the hormone may help
them control their weight by eating less. After all, one study
found that normal-weight people who received a shot of PYY
consumed about one-third less at an all-you-can-eat buffet
than their un-dosed counterparts. One challenge is that the
hormone can't be taken orally, since it would be digested
in the gut before it could ever reach the brain. Merck and
Nastech Pharmaceuticals have joined forces to circumvent the
problem by developing a nasal spray that will deliver PYY
directly to the bloodstream. They are in the early phases
of clinical trials now.
 |
 |
|
Cannabis
smokers often experience hunger pangs they call 'the
munchies;' scientists developed riminobant to have the
opposite effect.
|
|
Food
intake is also regulated through the endocannabinoid system,
sometimes described as the brain's reward or pleasure system.
For centuries, people have noted the 'munchies' that come
along with ingesting marijuana, a plant in the cannabis family.
Marijuana activates endocannabinoid receptors in the brain,
called CB1 receptors, that make people feel hungry. Obese
people have more of these receptors than normal weight people
do. Researchers designed a compound, called rimonabant, to
block CB1 receptors and they got the result they were looking
for — decreased appetite. Fat cells throughout the body
also have CB1 receptors, and blocking them changes the way
fat is metabolized. Like the other weight loss drugs, successful
patients who took rimonabant in trials lost around 5 or 10%
of their original body weight. They felt fuller, so they ate
less. According to the manufacturer, a bonus effect was decreased
levels of triglycerides and increased levels of good cholesterol
in patients' blood. Critics worry that interfering with this
particular brain system may have other unknown effects on
mental health. If approved by the FDA, the drug could be on
the market as Acomplia as early as 2006. 
--------------------------
3 pages: | 1 | 2 | 3
|
|
