In the U.S.—

• Substrate reduction therapy

Miglustat (MIH-glue-stat) is used to treat adults with mild to moderate type 1 Gaucher disease. Miglustat is only used in people who cannot be treated with enzyme replacement therapy. Type 1 Gaucher disease is a disease you get from both your parents. People with type 1 Gaucher disease are missing an enzyme (naturally occurring substance in your body) that breaks down a chemical in your body called glucosylceramide. Too much glucosylceramide causes liver and spleen enlargement, changes in the blood, and bone disease. Miglustat works by stopping the body from making glucosylceramide.

This medicine is available only with your doctor's prescription, in the following dosage forms:

• Capsules (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For miglustat, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to miglustat. Also tell your doctor and pharmacist if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Miglustat is not recommended during pregnancy. It has been shown to cause serious birth defects or other problems in animals. Before taking this medicine be sure your doctor knows if you are pregnant or are planning to become pregnant. Be sure you have discussed this with your doctor. Males who are taking this medicine should use effective birth control and should continue using birth control for at least three months after stopping the medicine.

Breast-feeding—It is not known whether miglustat passes into breast milk. It is not recommended for use during breast feeding because it may cause unwanted effects in nursing babies. You should decide to breast feed or take miglustat, but not both. Be sure you have discussed this with your doctor.

Children—This medicine is not used in children under 18 years of age.

Older adults—Many medicines have not been specifically studied in older people. Therefore, it may not be known whether they work the same way the do in younger adults. This medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

• Gaucher disease, Type 1, severe—this medicine is not currently being used in patients with severe Type 1 Gaucher disease

• Kidney disease—this condition may cause you to have more miglustat in your body; your doctor may want to change the amount of miglustat that you take

It is important to take miglustat exactly as your doctor prescribed. You should take your medicine at the same time or at the same times each day.

The capsules should be swallowed whole with water and may be taken with or without food. Check with your doctor or pharmacist if you have any questions.

Your doctor may recommend changes to your diet to help with some side effects. It is important that you follow these changes.

Dosing—

The dose of miglustat will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of miglustat. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage form (capsules):
  • For Mild to Moderate Type 1 Gaucher disease
    • Adults—One 100 milligram (mg) capsule given three times a day; your doctor may change this dose as needed
    • Children—Use is not recommended in children under the age of 18

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Keep the medicine from freezing. Do not refrigerate.
• Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.

Miglustat can cause problems affecting your nerves. If you have hand tremors (shaky movements) or if miglustat worsens a hand tremor you already have call your doctor. Your doctor might want to change your dose of miglustat.

If you experience numbness and tingling in your hands, arms, legs, or feet (peripheral neuropathy) call your doctor right away.

It is very important that your doctor check you at regular visits. Your doctor will also want to test your nerves (neurological exam) before you start taking miglustat and may repeat this test at a later time.

Diarrhea is the most common side effect for people taking miglustat. Your doctor may give you another medicine (anti-diarrheal) to help treat diarrhea if it is a problem for you. Your doctor may also recommend changes to your diet. You may also lose weight when you start treatment with miglustat.

It is very important to discuss with your doctor if you are pregnant or plan to become pregnant before starting miglustat. You should use effective birth control while taking miglustat. Miglustat may also harm a man's sperm. All men should use effective birth control during treatment and for three months after stopping treatment.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• More common
  • Black, tarry stools;  bleeding gums;  blood in urine or stools;  burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings;  pinpoint red spots on skin;  unusual bleeding or bruising 
  
  

• Unknown
  • Painful sensations;  shakiness in legs, arms, hands, feet;  trembling or shaking of hands or feet;  unsteadiness or awkwardness;  weakness in arms, hands, legs, or feet 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome.

• More Common
  • Acid or sour stomach;  back pain;  belching;  bloated, full feeling;  change in vision;  cramps;  diarrhea;  difficulty having a bowel movement (stool);  dizziness;  dry mouth;  excess air or gas in stomach or intestines ;  full or bloated feeling or pressure in the stomach ;  headache;  heartburn;  heaviness in limbs;  indigestion;  leg cramps;  loss of appetite;  memory loss;  menstrual changes;  nausea;  pain or discomfort in chest, upper stomach, or throat;  passing gas;  stomach discomfort, upset or pain;  swelling;  swelling of abdominal or stomach area;  unsteady walk;  vomiting;  weakness;  weight loss 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.