Xenical® Frequently Asked Questions

What is Xenical®?

Xenical®(orlistat) is a new weight control medication, just recently approve by the FDA, that has been widely tested throughout Europe. Distinct from other medicines that stimulate the brain to suppress appetite, Xenical® uses a fat blocking mode of action that works non-systematically in the gastrointestinal tract. The end result is approximately 30 percent of dietary fat passes through the body undigested.

How does Xenical® work?

Lipases, before they can be absorbed into the bloodstream. Xenical® interferes with these enzymes by forming covalent bonds with them in the stomach and small intestine, which essentially inactivates the enzymes so they are no longer available to hydrolyze dietary fat into an absorbable state. Thus allowing for approximately 30 percent of fat consumed in a meal to pass through the gastrointestinal system undigested.

What clinical studies have been completed?

Xenical® was evaluated in a placebo-controlled, double blind study to examine the effectiveness of a medication for weight loss and the prevention of weight regain over a two-year period.

During the first year, participants who met the definition of obese were placed on a low calorie diet while randomly given a placebo or orlistat. Research following the first year indicated those individuals treated with orlistat (120 mg per dose) lost approximately two-thirds more weight than the control (placebo) group.

In the second year, participants were placed on a weight maintenance diet and the orlistat group was randomized to receive either a placebo or different doses of orlistat. Results following the second year indicated the individuals on orlistat, 120 mg per dose, three times per day were two times as likely to keep the weight off as those individuals in the control (placebo) group.

"This study demonstrates that partial inhibition of fat absorption in obese subjects can produce sustained weight loss," the authors conclude. "Subjects treated with orlistat plus a mildly controlled-energy diet lost significantly more weight than those treated with placebo plus diet even though all subjects received a high standard of care and similar dietary counseling…These observations collectively suggest that orlistat may be a useful adjunct to dietary intervention in producing and maintaining weight loss over two years."

Journal of the American Medical Association (JAMA. 1999;281:235-242) What are the side effects of Xenical?

Secondary to the mechanism of action, blocking the absorption of dietary fat, most individuals experience some changes in bowel habits. These changes may include gas with discharge, an increase in the frequency of bowel movements, fatty or oily stools and sometimes the inability to control bowel movements. These symptoms generally occur early in the treatment and subside in a relatively short period of time. Adhering to the recommended diet, meals that contain no greater than 30 percent of the calories from fat may significantly reduce any side effects.

Are there any other benefits to taking Xenical® other than weight reduction?

Yes, studies have shown that even a modest weight loss as a result of Xenical® and diet can significantly reduce the following life-risk factors:

Weight reduction is also likely to improve appearance, which has a positive affect on self-esteem and motivation.

Which individuals benefit from Xenical®?

Xenical® is appropriate for those individuals who are considerably overweight, 30 percent above their ideal weight or a body mass index of 30 or greater. Xenical® may also be appropriate for those individuals who are overweight, 20 percent above their ideal weight or a body mass index of 27 or greater, and also have significant risk factors such as high blood pressure, high cholesterol or diabetes.

How does one determine their body mass index (BMI)?

BMI is calculated by dividing an individual's weight in kilograms by their height in meters squared.

The following chart can assist individuals in calculating their BMI:

Body Mass Index Chart

What is the appropriate dose of Xenical®?

The recommended dose of Xenical® is one 120-mg capsule taken with each meal that contains fat. Individuals may take Xenical® in combination with a moderately reduced calorie diet up to three times per day. In the event, a meal is without fat content or a meal is periodically missed an individual may omit that dose. Doses in excess of 120 mg three times per day have not proven to advantageous to weight reduction. For the best results, individuals should practice eating a well-balanced, moderately reduced calorie diet that contains no more than 30 percent of the calories from fat.

How long should an individual take Xenical®?

Xenical® has been proposed as a long-term treatment option for individuals who suffer from obesity. Orlistat, the active ingredient in Xenical® is believed to be safe because systemic exposure is minimal. In fact, approximately 97% of the administrative dose of orlistat was found excreted in the feces, 83% of that was found to be chemically unchanged orlistat. However, the use of Xenical® for more than two years has not been studied so extended use of the medicine, in excess of two years, is not recommended at this time.

What about missed doses?

If an individual forgets to take their medication, he or she should take it immediately when they remember, provided no longer than an hour has passed since the last meal. Do not double the dose or change the prescribed dose without the recommendation of a physician.

What about an Overdose?

Single does of 800mg of Xenical® and multiple doses up to 400mg three times a day for over two weeks have been studied in normal weight and obese patients without significant adverse findings. Should a significant overdose of Xenical® occur, individuals should seek immediate medical attention.

Does Xenical® interact with other medications?

Xenical® does not affect most commonly prescribed medications. However, it is important for individuals to communicate with their physicians concerning medications they are taking. This is relevant since taking more than one medication at any given time can result in drug interactions; medicines when combined can potentiate or lessen the effect of other medications. For example, Xenical® potentiates the lipid lowering the affect of Pravastatin while it decreases the absorption of the fat-soluble vitamins A, D, E, K and beta caratine.

Should I supplement a multi vitamin with Xenical®?

Yes, Xenical® interferes with the absorption of some fat-soluble vitamins. Therefore, it is recommended that individuals supplement their diet with a daily multi-vitamin that contains vitamins A, D, E, K plus beta-carotene. Multi vitamins should be taken once per day approximately two hours before or after taking Xenical®.

When is it inappropriate to take Xenical®?

Xenical® is contradicted in the following circumstances:

Should Xenical® be taken during pregnancy or while breastfeeding?

The safety of Xenical® has not been established in pregnant women, therefore Xenical® should not be used in women who are trying to get pregnant or in women who are pregnant. Women should not take Xenical® while breastfeeding their infant because it is not known whether Xenical® is excreted in the breast milk.

Is Xenical® appropriate for pediatric or geriatric populations?

The safety and efficiency of Xenical® in the pediatric population have not been established. In addition, clinical studies concerning Xenical® did not include a sufficient number of elderly individuals age 65 years and older to determine whether they respond differently from younger individuals. So at this time pediatric and geriatric populations should refrain from using Xenical® until more studies are completed.

How is Xenical® supplied?

Each capsule contains 120 mg of the active ingredient orlistat. The capsule also contains the inactive ingredients microcrystalline cellulose, sodium starch glycolate, sodium lauryl sulfate, povidone and talc. The capsule shell consists of gelatin, titanium dioxide and FD2C Blue No.1.

Can I get Xenical® over the counter?

No. Xenical® is a prescription medication and should only be taken when prescribed by a licensed physician. FDA regulations do not permit Xenical® to be taken without a prescription.