In the U.S.—

• Tyrosine degradation inhibitor

Nitisinone (ni-TIS-uh-none) is given along with a special diet to treat hereditary tyrosinemia, type 1. This disease is caused by too much tyrosine in the blood. It may cause damage to the liver, kidneys, eyes, skin, and nervous system. Treatment with nitisinone and diet may slow the disease, but it will not cure it.

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

Oral
• 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 nitisinone, the following should be considered:

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

Pregnancy—Nitisinone has not been studied in pregnant women. However, studies in rats have shown that nitisinone causes reduced litter size, low birth weight and decreased survival after birth. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding— It is not known whether nitisinone passes into human breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children—This medicine has been tested in children and, in effective doses, has not been shown to cause specific problems.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of nitisinone in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you or your child is taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

To use:

• It is not known how nitisinone reacts with food. It is best to take it at least 1 hour before a meal.
• For small children, you may open the capsule and put the medicine in a small amount of water, formula, or applesauce. Give the medicine as soon as it is mixed.

Dosing—

The dose of nitisinone will be different for different patients. Follow your doctor's orders or the directions on the label.

The number of capsules that you or your child takes depends on the strength of the medicine.

• For oral dosage form (capsules):
  • For hereditary tyrosinemia, type 1:
    • Adults—The dose is based on body weight and will be determined by your doctor. Your doctor may increase the dose as needed.
    • Children—The dose is based on body weight and will be determined by your child's doctor. Your child's doctor may increase the dose as needed.

Missed dose—

If a dose of this medicine is missed, take it as soon as possible. However, if it is almost time, 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.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. heat or moisture may cause the medicine to break down.
• Store in the refrigerator. However, keep the medicine from freezing.
• 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.

While taking this medicine,it is important that you or your child maintain a diet with restricted amounts of tyrosine and phenylalanine A nutritionist may be able to help you with the special diet needed to treat you. A nutritionist that has special training with children may help with a diet for your child.

Call your doctor right away for any redness, swelling, or burning of your or your child's eyes, an unusual rash, bleeding, or if your or your child's skin is yellow.

It is very important that the doctor check you or your child at regular visits to see how the medicine is working and increase the dose if needed. The doctor may test your your child's blood often.

A special examination of your or your child's eyes should be done before this medicine is started.

Wearing sunglasses that block ultraviolet light is recommended. Nitisinone may cause sensitivity of the eyes to the sunlight.

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 the doctor immediately if any of the following side effects occur:

• More common
  • Bloated abdomen;  dark-colored urine ;  dull, achy upper abdominal pain;  general feeling of tiredness or weakness;  headache ;  light-colored stools;  loss of appetite;  unexplained weight loss;  vomiting;  yellow eyes or skin 
  
  

• Less common
  • Black, tarry stools 
  
  
  • blindness;  blood in urine or stools ;  blisters on skin;  bloody nose;  blurred vision;  change in color vision;  chest pain or discomfort;  chills;  cough;  darkening of urine;  decreased vision;  difficulty seeing at night;  dry or itching eyes;  dry skin;  excessive tearing from eyes;  eye pain;  fever;  fluid-filled skin blisters;  general feeling of discomfort or illness;  increased sensitivity of eyes to sunlight;  irritation or inflammation of the eye;  itching of the skin;  painful or difficult urination;  pinpoint red spots on skin;  rash with flat lesions or small raised lesions on the skin;  red, thickened, or scaly skin;  redness, pain, swelling of eye, eyelid, or inner lining of eyelid burning;  sensitivity to the sun;  shortness of breath;  skin thinness;  sore throat;  sores, ulcers, or white spots on lips or in mouth;  swollen and/or painful glands;  unusual bleeding or bruising;  unexplained nosebleed 
  
  

• Rare
  • Agitation;  anxiety;  back pain;  bloody stools;  bluish color of fingernails, lips, skin, palms, or nail beds;  change in personality;  change in vision ;  cold sweats;  coma;  confusion;  cool, pale skin;  cough producing mucus;  decreased urination ;  diarrhea;  difficulty breathing ;  dizziness;  drowsiness ;  dry mouth;  earache;  fainting;  fast heartbeat;  feeling full in upper abdomen;  increase in heart rate;  increase in body movements;  increased hunger;  infection;  irregular, fast or slow, or shallow breathing;  irritability;  lightheadedness;  mood or mental changes;  nausea;  nervousness;  pain or swelling in arms or legs without any injury;  pale skin;  problems with walking or talking;  rapid breathing ;  redness or swelling in ear;  seeing things that are not there;  shakiness;  skin rash found mostly on mucous membranes such as eyes and mouth ;  stiff neck;  sunken eyes ;  thirst;  tightness in chest ;  vomiting of blood or material that looks like coffee grounds;  wheezing;  wrinkled skin 
  
  

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

• Less common or rare
  • Absent, missed, or irregular menstrual periods;  burning feeling in chest or stomach;  hair loss;  indigestion;  sleepiness;  stomach upset;  stopping of menstrual bleeding;  tenderness in stomach area;  thinning of hair;  tooth discoloration 
  
  

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