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Generic Name: orlistat (OR li stat)
Brand Names: alli, Xenical

What is Xenical?

Xenical (orlistat) blocks some of the fat that you eat, keeping it from being absorbed by your body.

Xenical is used to aid in weight loss, or to help reduce the risk of regaining weight already lost. This medicine must be used together with a reduced-calorie diet. Xenical is for use only in adults.

Orlistat is also available over-the-counter under the brand name alli for customers over the age of 18 years.

It is dangerous to purchase Xenical on the Internet or from vendors outside of the United States. Medications distributed from Internet sales may contain dangerous ingredients, or may not be distributed by a licensed pharmacy. Samples of "alli" purchased on the Internet have been found to contain sibutramine (Meridia), a prescription weight loss medication that can have dangerous side effects in certain people. For more information, contact the U.S. Food and Drug Administration (FDA) or visit www.fda.gov/buyonlineguide.

Important information

Do not take Xenical if you are pregnant. Weight loss is not recommended during pregnancy, even if you are overweight or obese.

You should not take Xenical if you have gallbladder problems or chronic malabsorption syndrome (an inability to absorb food and nutrients properly).

Before taking Xenical, tell your doctor if you have an underactive thyroid, a history of gallstones or pancreatitis, type 1 or type 2 diabetes, an eating disorder, liver disease, or if you take other weight-loss medications (prescription or over-the-counter).

Slideshow: Newly Approved Weight Loss Drugs - Can They Help You?

Xenical should not be used by anyone age 12 to 18 without the advice of a doctor. This medication should be used only by the person it was prescribed or recommended for and should never be shared with another person, especially someone who has a history of eating disorder. Keep the medication in a place where others cannot get to it.

Xenical is only part of a complete program of treatment that also includes diet, exercise, and weight control. Your daily intake of fat, protein, and carbohydrates should be evenly divided over all of your daily meals. Follow your diet, medication, and exercise routines very closely.

Avoid a diet that is high in fat. High-fat meals taken in combination with Xenical can increase your risk of unpleasant side effects on your stomach or intestines.

Before taking this medicine

You should not take Xenical if you are allergic to orlistat, or if you have:

  • gallbladder problems;

  • chronic malabsorption syndrome (an inability to absorb food and nutrients properly); or

  • if you are pregnant.

To make sure Xenical is safe for you, tell your doctor if you have:

  • liver disease;

  • kidney disease;

  • a history of gallstones or kidney stones;

  • underactive thyroid;

  • a history of pancreatitis;

  • type 1 or type 2 diabetes;

  • an eating disorder (anorexia or bulimia); or

  • if you take any other weight-loss medications (prescription or over-the-counter).

FDA pregnancy category X. Do not use Xenical if you are pregnant. Weight loss is not recommended during pregnancy, even if you are overweight or obese. Stop taking Xenical and tell your doctor right away if you become pregnant.

See also: Pregnancy and breastfeeding warnings (in more detail)

Taking orlistat can make it harder for your body to absorb certain vitamins. These vitamins are important if you are nursing a baby. Tell your doctor if you are breast-feeding a baby.

How should I take Xenical?

Take Xenical exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Never share Xenical with another person, especially someone who has a history of eating disorder. Keep the medication in a place where others cannot get to it.

This medicine comes with patient instructions for safe and effective use. Follow these directions carefully. Ask your doctor or pharmacist if you have any questions.

Xenical is usually taken 3 times per day with each main meal that contains some fat (no more than 30% of the calories for that meal). You may take the medicine either with your meal or up to 1 hour after eating.

If you skip a meal or you eat a meal that does not contain any fat, skip your Xenical dose for that meal.

The fat content of your daily diet should not be greater than 30% of your total daily caloric intake. For example, if you eat 1200 calories per day, no more than 360 of those calories should be in the form of fat.

Read the label of all food items you consume, paying special attention to the number of servings per container. Your doctor, nutrition counselor, or dietitian can help you develop a healthy eating plan.

Xenical is only part of a complete program of treatment that also includes diet, exercise, and weight control. Your daily intake of fat, protein, and carbohydrates should be evenly divided over all of your daily meals. Follow your diet, medication, and exercise routines very closely.

Xenical can make it harder for your body to absorb fat-soluble vitamins, such as vitamins A, D, E, and K. Your doctor may recommend that you take vitamin and mineral supplements while you are taking Xenical. Follow your doctor's instructions about the type of multi-vitamin or mineral supplement to use.

Take your vitamin or supplement at bedtime, or at least 2 hours before or after you take Xenical.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed. Throw away any unused Xenical after the expiration date on the medicine label has passed.

Keep track of the amount of medicine used from each new bottle. Xenical is a drug that may be misused as a weight-loss aid, and you should be aware if anyone is using your medicine improperly or without a prescription.

Xenical dosing information

Usual Adult Dose for Obesity:

120 mg orally three times a day with each main meal containing fat. The dose may be taken during the meal or within 1 hour of completing the meal.

Usual Pediatric Dose for Obesity:

12 years or older:
120 mg orally three times a day with each main meal containing fat. The dose may be taken during the meal or within 1 hour of completing the meal.

What happens if I miss a dose?

Take the missed dose as soon as you remember, but no more than 1 hour after eating a meal. If it has been more than an hour since your last meal, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Xenical?

Avoid a diet that is high in fat. High-fat meals taken in combination with Xenical can increase your risk of unpleasant side effects on your stomach or intestines.

If you also take cyclosporine, do not take it within 3 hours before or 3 hours after you take Xenical.

If you also take levothyroxine (such as Synthroid), do not take it within 4 hours before or 4 hours after you take Xenical.

Xenical side effects

Get emergency medical help if you have any of these signs of an allergic reaction to Xenical: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using Xenical and call your doctor at once if you have:

  • severe pain in your lower back;

  • blood in your urine, painful or difficult urination;

  • kidney problems--little or no urinating; swelling in your feet or ankles; feeling tired or short of breath; or

  • liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common Xenical side effects are caused by orlistat's fat-blocking action. These are signs that the medicine is working properly. These side effects are usually temporary and may lessen as you continue using Xenical:

  • oily or fatty stools;

  • oily spotting in your undergarments;

  • orange or brown colored oil in your stool;

  • gas and oily discharge;

  • loose stools, or an urgent need to go to the bathroom, inability to control bowel movements;

  • an increased number of bowel movements; or

  • stomach pain, nausea, rectal pain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Xenical?

Tell your doctor about all medicines you use, and those you start or stop using during your treatment with Xenical, especially:

  • insulin or oral diabetes medicine;

  • seizure medication (especially if your seizures get worse while taking orlistat);

  • a vitamin or mineral supplement that contains beta carotene or vitamin E; or

  • warfarin (Coumadin, Jantoven).

This list is not complete. Other drugs may interact with orlistat, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Where can I get more information?

  • Your pharmacist can provide more information about Xenical.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2015 Cerner Multum, Inc. Version: 11.02. Revision Date: 2015-01-09, 10:09:51 AM.

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