Generic Name: nitisinone (ni TIZ i none)Brand Names: Orfadin
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. The symptoms of HT-1 include unusual bleeding and signs of liver failure, such as dark urine, jaundice (yellowing of the skin or eyes), sudden stomach pain, nausea, vomiting, diarrhea, and fatigue.
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 only part of a complete program of treatment that also includes a special diet. It is very important to follow the diet plan created for you by your doctor or nutrition counselor. You should become very familiar with the list of foods you must avoid to help control your condition.You may experience side effects that are caused by nitisinone. Similar side effects may also be caused by your diet. Call your doctor immediately if you have jaundice (yellowing of the skin or eyes), unusual bleeding, vision changes, or eye redness, pain, burning, or sensitivity to light.
Before taking nitisinone, tell your doctor if you have eye pain, redness, or swelling, or if your eyes are more sensitive to light than usual. You may need to have an eye examination.
While you are taking nitisinone, your doctor may recommend regular visits to check your liver with blood tests and ultrasounds or CT scans.Some side effects may result from not properly following your diet plan and consuming restricted foods or beverages. Call your doctor if you develop eye redness, pain, burning, or sensitivity to light; painful overgrowth of skin on the palms of your hands or the soles of your feet; changes in behavior; or delayed developmental milestones in a baby such as walking, talking, sitting up, or rolling over. Nitisinone is in the FDA pregnancy category C. This means that it is not known whether nitisinone will be harmful to an unborn baby. Although it is unlikely that a child taking nitisinone would become pregnant, the medicine may also be used in women of child-bearing age. Do not take nitisinone without telling your doctor if you are pregnant. It is not known whether nitisinone passes into breast milk. Do not use nitisinone without telling your doctor if you are breast-feeding a baby.
To make it easier to swallow the medicine, you may open a capsule and sprinkle the contents into a small amount of water, infant formula, or applesauce. Use this mixture right away and do not keep it for later use.Store this medication in the refrigerator and do not allow it to freeze.
Take the missed dose as soon as you remember. If it is almost time for your next regularly scheduled dose, skip the missed dose and take your next dose as directed.. Do not take extra medicine to make up the missed dose.
Symptoms of a nitisinone overdose may include skin rash, jaundice (yellowing of the skin or eyes), unusual bleeding, or problems with your eyes or vision.
Some of the foods that contain tyrosine include cheese, milk, sour cream, beer, wine, distilled liquor, chicken, beef, liver, fish, processed meats (bologna, hot dogs, pepperoni, hard sausages), meat tenderizer, herring or other dried fish, avocados, bananas, carrots, potatoes, oatmeal, brown rice, soy sauce, spinach, tomatoes, bean curd, raisins, red plums, garbanzo beans, soy beans, and almonds.
Foods that contain phenylalanine include diet sodas, beef, poultry, pork, fish, milk, yougurt, eggs, cheese, soybeans, soy protein, tofu, and certain nuts or seeds.
A major source of phenylalanine is the artificial sweetener aspartame (NutraSweet), which is contained in many diet or sugar-free drinks and food products. Before consuming any packaged food or beverage, carefully read the nutrition label to be sure the product does not contain phenylalanine or have a warning about phenylketonuria.
There are other foods that may contain tyrosine or phenylalanine. Be sure you are familiar with the list of foods you must avoid or restrict to help control your condition.
an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
jaundice (yellowing of the skin or eyes);
eye redness, pain, burning, or sensitivity to light;
bloody or black stools; or
unusual bruising or bleeding.
Other, less serious side effects may be more likely to occur. Continue using nitisinone and talk with your doctor if you have any of these side effects:
fever, sore throat, cough, muscle aches;
itching or peeling of your skin;
diarrhea, nausea, or constipation;
nervousness, trouble sleeping;
mild stomach pain or diarrhea.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.
There may be other drugs that can affect nitisinone. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.