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Generic Name: nitisinone (nye TIS i none)
Brand Name: Orfadin, Nityr

Medically reviewed by on Apr 4, 2019 – Written by Cerner Multum

What is nitisinone?

Nitisinone works by preventing the body from breaking down an amino acid called tyrosine and by keeping other toxic substances from building up and causing harm to your liver or kidneys.

Nitisinone is used to treat a rare genetic condition called hereditary tyrosinemia type 1 (HT-1). HT-1 is a metabolic disorder that occurs when the body does not produce enough of an enzyme that breaks down proteins from certain foods. This condition occurs most often in young babies.

Nitisinone may also be used for purposes not listed in this medication guide.

Important Information

Call your doctor at once if you have vision problems, eye pain, eye redness or burning, easy bruising, unusual bleeding, itching, or jaundice (yellowing of the skin or eyes). Tell your doctor if your baby has a sudden change in behavior, ability, or development (sitting up, crawling, walking, talking, etc).

Before taking this medicine

To make sure nitisinone is safe for you, tell your doctor if you have any medical conditions affecting your eyes.

It is not known whether nitisinone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while taking this medicine.

It is not known whether nitisinone passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

How should I take nitisinone?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Your doctor may occasionally change your dose to make sure you get the best results. Do not change your medication dose or schedule without your doctor's advice.

Take the nitisinone capsule on an empty stomach, at least 1 hour before or 2 hours after a meal.

You may take nitisinone liquid with or without food.

You may open the nitisinone capsule and sprinkle the medicine into a spoonful of water, baby formula, or applesauce to make swallowing easier. Use the mixture right away. Do not save for later use.

Shake the oral suspension (liquid) for at least 5 full seconds just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Nitisinone may be only part of a complete program of treatment that also includes a special diet. You must avoid certain foods for your treatment to be effective. Follow the diet plan created for you by your doctor or nutrition counselor.

High protein foods are high in tyrosine and phenylalanine. Since babies and children need protein to grow and develop, special foods have been developed to replace the high protein foods.

While using nitisinone, you may need frequent blood tests at your doctor's office. Your vision may also need to be checked.

Store nitisinone capsules or liquid in the refrigerator, do not freeze.

After using nitisinone liquid for the first time, you may store the medicine at room temperature for up to 60 days.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. 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 nitisinone?

While you are taking nitisinone, you must not eat foods that are high in tyrosine or phenylalanine, including:

  • chicken, beef, pork, liver, fish, processed meats (bologna, hot dogs, pepperoni, hard sausages), meat tenderizer, herring or other dried fish;

  • cheese, milk, sour cream, yogurt;

  • beer, wine, distilled liquor;

  • avocados, bananas, carrots, potatoes, spinach, tomatoes, raisins, red plums,

  • oatmeal, brown rice,

  • soy sauce, soy protein, tofu, bean curd, garbanzo beans, soy beans, and certain nuts or seeds; or

  • foods that contain an artificial sweetener called aspartame (NutraSweet)--diet soda, some foods labeled as "sugar-free" or "zero calorie."

There are other foods that may contain tyrosine or phenylalanine. Get familiar with the list of foods you must avoid to help control your condition.

Nitisinone side effects

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

Some side effects may result from not properly following your diet plan and consuming restricted foods or beverages.

Call your doctor at once if you have:

  • a sudden change in behavior, ability, or development (sitting up, crawling, walking, talking, etc);

  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;

  • nausea, diarrhea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

  • vision problems;

  • eye pain, redness or swelling, burning, white or yellow patches on your eyes; or

  • calluses, peeling, or hardened skin on the palms of your hands or the soles of your feet.

Common side effects may include:

  • vision changes;

  • red or puffy eyes;

  • nosebleeds;

  • increased sensitivity of your eyes to light;

  • mild rash or itching;

  • dry skin; or

  • thinning hair.

The liquid form of nitisinone may contain glycerol and can cause headache, upset stomach, or diarrhea.

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.

What other drugs will affect nitisinone?

Other drugs may interact with nitisinone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

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.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.