Pharmacy Author: Omudhome Ogbru, PharmD
Medical and Pharmacy Editor: Jay W. Marks, MD
GENERIC NAME: orlistat
BRAND NAME: Xenical, Alli
 |
Alli (orlistat) Weight Loss Drug Available OTC
Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel, Jr., MD, FACP, FACR
The U.S. Food and Drug Administration approved orlistat capsules, branded as alli,
as an over-the-counter (OTC) treatment
for overweight adults in
February, 2007. The drug had previously been approved in 1999 as a
prescription weight loss aid, whose brand name is Xenical.
The OTC preparation will have a lower dosage than
prescription Xenical and is produced and sold by GlaxoSmithKline under the
name of alli.
Unlike appetite suppressants, orlistat (Xenical) works as a weight loss aid by acting
upon the function of the gastrointestinal tract. The drug binds to an enzyme known as gastrointestinal lipase and
inhibits the action of this enzyme, which plays a role in breaking down fats for
absorption in the GI tract. As a result, up to 30% of ingested fat is not absorbed by the body.
|
 |
DRUG CLASS AND MECHANISM: Orlistat is a drug that promotes loss of
weight by preventing the digestion and absorption of fat in food. In the
intestine, an enzyme called lipase (produced primarily by the pancreas) breaks
apart fat in food so that it can be absorbed into the body. Orlistat blocks the
action of lipase and thereby prevents the breakup and absorption of fat.
Orlistat blocks absorption of about 25% of the fat in a meal. The unabsorbed fat
is excreted in the stool. The FDA approved Orlistat by prescription in 1999.
alli, a lower dose formulation of orlistat, was approved for purchase without a
prescription "over the counter" in 2007.
PRESCRIPTION: Orlistat yes, alli no
GENERIC AVAILABLE: No
PREPARATIONS: Capsules: 60 mg (alli), 120 mg
(Xenical)
STORAGE: Capsules should be stored at room temperature, 15-30°C
(59-86°F)
PRESCRIBED FOR: Orlistat is combined with a reduced-calorie diet to promote
weight loss. Orlistat also may be used to prevent weight gain after weight has
been lost. Candidates for treatment with orlistat are patients who are obese
with a body mass index (a measure of obesity) of more than 30 kg/m2. Candidates
also include patients with a body mass index of between 27 and 30 kg/m2 if other
risk factors for arteriosclerosis are present such as high blood pressure,
diabetes, and elevated blood cholesterol or triglycerides. Based on several
scientific studies, the average weight loss that is achieved when orlistat is
taken as recommended for six months to one year is 12.4 to 13.4 pounds.
DOSING: The recommended prescription dose for Xenical is one capsule (120 mg)
three times daily. The recommended dose for alli is 60 mg three times daily.
Orlistat should be taken one hour after or during a meal containing about 15 mg
of fat. Meals without fat do not require orlistat. No additional benefit has
been shown when orlistat was taken in doses greater than 120 mg. Patients should
eat a nutritionally balanced, reduced calorie diet that contains approximately
30% of calories from fat. alli includes an individually tailored online weight
loss support program.
Some dietary vitamins bind to fat (vitamins A, D, E and beta- carotene). When
orlistat is taken, these vitamins are not absorbed and are eliminated in the
stool in increased amounts along with the fat. Therefore, patients taking
orlistat should take a multivitamin containing these "fat-soluble" vitamins to
ensure that adequate amounts of the vitamins are available for absorption. To
ensure that the vitamins in the multivitamins are not bound to fat like the
vitamins in the diet, the multivitamin should be taken at least two hours before
or several hours after the orlistat.
DRUG INTERACTIONS: The blood thinning effect of warfarin (Coumadin) depends
on the amount of vitamin K in the body, and vitamin K is one of the vitamins
that binds to fat. Patients receiving warfarin who begin orlistat should have
their blood clotting monitored closely because the orlistat may cause levels of
vitamin K to decline. This will increase the effects of warfarin and lead to
abnormal bleeding from the warfarin. There is no evidence that a deficiency of
vitamin K occurs in patients who are taking orlistat.
Orlistat may reduce the absorption and blood levels of cyclosporine
(Sandimmune) when both drugs are administered together. Therefore, cyclosporine
should be administered two hours before or after orlistat, and more frequent
monitoring of cyclosporine levels may be needed.
Hypothyroidism has been reported when orlistat and levothyroxine were
combined. Patients treated with both orlistat and levothyroxine should be
monitored for changes in thyroid function. The orlistat and levothyroxine
should be taken at least four hours apart.
PREGNANCY: Safe use of orlistat during pregnancy has not been established.
Therefore, orlistat is not recommended during pregnancy.
NURSING MOTHERS: It is not known if orlistat is secreted in breast milk.
Therefore, it probably should not be taken by nursing mothers.
SIDE EFFECTS: The most common side effects of orlistat are oily spotting on
underwear, flatulence, urgent bowel movements, fatty or oily stools, increased
number of bowel movements, abdominal pain or discomfort, and inability to
control stool (incontinence). Between 1 in 250 and 1 in 70 patients experienced
one or more of these symptoms in the first year. Generally, the side effects
occurred within three months of starting therapy. In about 50% of patients, the
side effects resolved within one to four weeks, but the effects in some patients
lasted six months or longer. To reduce the occurrence of these side effects,
meals should contain no more than 30% fat because it is the unabsorbed fat that
causes most of the symptoms. alli causes fewer side effects because it contains
half the dose of prescription-strength orlistat. Patients receiving orlistat
with a history of oxalate kidney stones may develop increased levels of oxalate
in their urine, which may increase the risk of kidney stones.
Additional drug information:
Xenical (orlistat) FDA approved labeling at RxList.
http://www.rxlist.com/xenical-drug/article.htm
Last Editorial Review: 6/18/2007
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
- Obesity - Learn about obesity and being overweight including the health risks, causes, review of weight loss diet plans, surgical and non-surgical treatments, and medications to treat the disease.
Latest Medical News
Back to Medications Index
Specialty RSS
