Orlistat
(Brand
Names: Alli or Xenical)
How it works
Orlistat
(brand names Alli or Xenical)
works on an enzyme in your intestines called
lipase.
This enzyme breaks down the fat that you eat. If it cannot be broken
down, it cannot be absorbed by your intestines. Alli binds to
lipase and prevents it from breaking down
fat. It
acts as a fat blocker and prevents the absorption of about 30% of the
fat in a person’s diet. Because the calories in this fat do not get
absorbed, you should lose weight. It does not block the absorption of
other types of calories such as from
protein
or
carbohydrates. Pros Orlistat (Alli
or Xenical) has been shown to help people lose weight. There is a study
done on this drug that lasted four years. This means that we know how
safe it is after people use it for four years. Most other weight loss
drugs have studies that lasted only one year. The body’s absorption of
the drug itself is minimal. This means that side effects should not
affect the rest of the body. This medicine seems to lower
cholesterol
levels more than just weight loss alone. This is probably because it
blocks the absorption of fats that can make up the bad (or LDL)
cholesterol. It can lower total cholesterol by about 5 points. Orlistat
may even be able to help reduce diastolic blood pressure (the bottom BP
number) by 2 points (mmHg) after 2 years. Cons There are some vitamins that
get absorbed along with fat. They are
Vitamins
A, D, and E
as well as carotenoids such as
beta-carotene.
Vitamin D is most affected. This may be overcome by taking a vitamin
supplement that has these vitamins and should be taken 2 hours before
or 1 hour after Alli. Vitamin supplements are not able to
make
up for the inability to absorb the caretenoids. Anyone with bone
problems or at risk of
osteoporosis
should discuss this with their doctor. Alli should also not be
taken by people who have chronic malabsorption syndrome or a
gallbladder
that does not move bile well. The
major side effects are stomach rumbling (borborygmi), cramps,
flatulence (....also called farts), some inability to hold bowel
movements, and oily spotting stool. Aside from embarrassing, these side
effects are for the most part, harmless. They may help a person on this
weight loss drug be more motivated and conscientious about having a
low fat diet.
The less fat in the diet, the less these side effects should occur. In
a sense, this con could really be a pro. Other Comments Like the other weight loss
medicines, lifestyle changes were part of the studies.
Diet
and
exercise
must be continued when using this medicine in order to get the maximal
effect.
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Weight Loss Drugs.
It is important you
discuss any weight loss or exercise plan with your doctor. Only you and
your physician can decide what is best for you. Some people have
certain conditions that prevent them from doing all exercises, and goal
body weights may be different for different people. You need to discuss
all these things with your physician before starting any weight loss or
exercise program. References
Ann
Intern Med 2005;142:525-531
“Drug therapy of Obesity” UpToDate
version 15.3
The Medical Letter on Drugs and Therapeutics
1999;41:55-56
The Medical Letter on Drugs and Therapeutics
2007;49:49
Treatment
Guidelines from the Medical Letter 2008;6:23-28
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