nitisinone

Nitisinone is used to treat a certain inherited disorder (hereditary tyrosinemia type 1, also known as HT-1). HT-1 is usually discovered in infants and needs lifelong treatment. This condition is caused by a shortage of a certain natural substance that is needed to break down a nutrient (tyrosine) found in food. This effect causes a build-up of too much tyrosine and related substances in the liver. Nitisinone works by helping to prevent the formation and build-up of several toxic substances that cause damage to the liver, kidneys, and nervous system. This drug must be used along with a diet low in protein, tyrosine, and phenylalanine.

Take this medication by mouth as directed by your doctor, usually twice daily.

If you are taking the capsules, take them on an empty stomach at least 1 hour before or 2 hours after a meal. If you are unable to swallow the capsules and/or have side effects with the suspension, you may open up the capsules and mix the contents in a small amount of water, formula, or apple sauce immediately before use.

If you are taking the suspension, read the Patient Information Leaflet provided by your pharmacist before you start taking it and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Shake the bottle well before each dose. Carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose. You may take the suspension with or without food. When using an unopened bottle of suspension for the first time, remove it from the refrigerator and let it warm to room temperature for 30 to 60 minutes before use.

If you are taking the tablets, read the Patient Information Leaflet if available from your pharmacist before you start taking nitisinone and each time you get a refill. You may take the tablets with or without food. If you are unable to swallow the tablets, you may crush the tablets and mix them in a small amount of water or applesauce. Take the mixture right away. If you are using a special measuring device/syringe to prepare and give the tablets mixed with water, carefully follow the directions from the manufacturer. Ask your doctor or pharmacist if you have any questions.

The dosage is based on your medical condition, weight, and response to treatment. Your doctor may adjust your dose and schedule based on your response to treatment. Carefully follow your doctor's directions for taking this medication.

Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.

It is very important that patients taking this medication follow a special diet low in protein, tyrosine, and phenylalanine. Consult your doctor, pharmacist, or dietician for more details. (See also Drug Interactions and Precautions sections.) Nitisinone can increase tyrosine levels and cause eye problems. Patients should have an eye test (slit-lamp examination) before using this medication so that later the doctor can see whether there have been changes. (See also Side Effects and Precautions sections.)

The suspension may cause headache, upset stomach, or diarrhea. If any of these effects occur, tell your doctor or pharmacist promptly and discuss switching to other forms of nitisinone.

Remember that the doctor has prescribed this medication because he or she has judged that the benefit is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication may rarely cause a low number of blood cells such as white cells and platelets. This effect can decrease your body's ability to fight an infection or cause easy bruising/bleeding. Tell your doctor right away if you develop any of the following unlikely symptoms: signs of infection (such as fever, chills, persistent sore throat), easy bruising/bleeding.

Your condition and this medication can cause liver problems. Tell the doctor right away if any of these symptoms of liver problems occur: severe stomach/abdominal pain, persistent nausea or vomiting, yellowing eyes/skin, dark urine.

Your condition and this medication can cause high levels of tyrosine in the blood. Therefore, it is very important to follow the low protein/low tyrosine diet recommended by your doctor. See also Precautions section. Too much tyrosine may cause skin, eye, or brain problems. Tell the doctor right away if any of these symptoms occur: eye redness/itching/discharge, vision changes, eye pain, eye sensitivity (especially to light), dry/itchy skin, sores on palms of hands/soles of feet, developmental delays (such as holding head up, rolling over, crawling).

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact the doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before giving nitisinone, tell the doctor or pharmacist if your child is allergic to it; or if your child has any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell the doctor or pharmacist your child's medical history, especially of: eye problems (such as cataracts, corneal ulcers).

Patients taking this medication are at risk for developing high levels of tyrosine in the blood, possibly leading to eye, skin, and nervous system problems. (See Side effects section.) To decrease the risk of high tyrosine levels, patients should follow a diet low in tyrosine and phenylalanine. Avoid foods and beverages that contain aspartame or are high in tyrosine or phenylalanine. Foods high in tyrosine include soy products, turkey, fish, avocados, bananas, yogurt, and lima beans. Foods high in phenylalanine include milk, chicken, eggs, cheese, peanut butter. (See also Drug Interactions section.) During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

Store the tablets at room temperature. Store the capsules in the refrigerator. Store the suspension in the refrigerator before the first use. Do not freeze. After the first use, store the bottle of suspension at room temperature. Discard any unused liquid 60 days after the date the bottle was removed from the refrigerator. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Many foods, drugs, or supplements may contain aspartame, tyrosine, or phenylalanine, which must be limited in patients taking this drug. Check the labels on all products (especially artificially sweetened products) for aspartame, tyrosine and phenylalanine content. Consult your doctor, pharmacist, or dietician for more details.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Do not share this medication with others.

Laboratory and/or medical tests (such as compete blood count, liver function tests, blood and urine tests for tyrosine and related substances) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.