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Orfadin Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 4/08/2016

Orfadin (nitisinone) is a hydroxyphenyl-pyruvate dioxygenase inhibitor 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 babies. Orfadin works by helping to prevent the formation and build-up of several toxic substances that cause damage to the liver, kidneys, and nervous system. Many people using Orfadin do not have serious side effects. Side effects of Orfadin may include:

  • cough
  • muscle aches
  • itching or peeling of your skin
  • diarrhea
  • nausea
  • constipation
  • nervousness
  • trouble sleeping
  • thirst
  • mild stomach pain, or
  • diarrhea
Orfadin may rarely cause the side effect of a low number of blood cells such as white cells and platelets. Tell your doctor if you have signs of infection (such as fever, chills, persistent sore throat), or easy bruising/bleeding.

The recommended dose of Orfadin is 1 to 2 mg/kg divided into two daily doses. The initial dose is 1 mg/kg/day divided for morning and evening administration. Other drugs may interact with Orfadin. Tell your doctor all medications and supplements you use. During pregnancy, Orfadin should be used only when prescribed. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Our Orfadin (nitisinone) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

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 is Patient Information in Detail?

Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.

Orfadin in Detail - Patient Information: Side Effects

Stop using nitisinone and get emergency medical help if you have any of these serious side side effects. Some of these side effects can be caused by the medication or by your diet:

  • 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;
  • vision changes;
  • 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;
  • thirst; or
  • 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.

Read the entire detailed patient monograph for Orfadin (Nitisinone)

What is Patient Information Overview?

A concise overview of the drug for the patient or caregiver from First DataBank.

Orfadin Overview - Patient Information: Side Effects

SIDE EFFECTS: 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 immediately 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 immediately 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 immediately 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.

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

Read the entire patient information overview for Orfadin (Nitisinone)

What is Prescribing information?

The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.

Orfadin FDA Prescribing Information: Side Effects
(Adverse Reactions)


Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

ORFADIN was studied in one open-label, uncontrolled study of 207 patients with HT-1, ages 0 to 21.7 years at enrollment (median age 9 months), who were diagnosed with HT-1 by the presence of succinylacetone in the urine or plasma. The starting dose of ORFADIN was 0.3 to 0.5 mg/kg twice daily, and the dose was increased in some patients to 1 mg/kg twice daily based on weight, biochemical, and enzyme markers. The recommended dose is 0.5 mg/kg to 1 mg/kg twice daily [see DOSAGE AND ADMINISTRATION]. Median duration of treatment was 22.2 months (range 0.1 to 80 months).

The most serious adverse reactions reported during ORFADIN treatment were thrombocytopenia, leukopenia, porphyria, and ocular/visual complaints associated with elevated tyrosine levels [see WARNINGS AND PRECAUTIONS]. Fourteen patients experienced ocular/visual events. The duration of the symptoms varied from 5 days to 2 years. Six patients had thrombocytopenia, three of which had platelet counts 30,000/microL or lower. In 4 patients with thrombocytopenia, platelet counts gradually returned to normal (duration up to 47 days) without change in ORFADIN dose. No patients developed infections or bleeding as a result of the episodes of leukopenia and thrombocytopenia.

Patients with HT-1 are at increased risk of developing porphyric crises, hepatic neoplasms, and liver failure requiring liver transplantation. These complications of HT1 were observed in patients treated with nitisinone for a median of 22 months during the clinical trial (liver transplantation 13%, liver failure 7%, malignant hepatic neoplasms 5%, benign hepatic neoplasms 3%, porphyria 1%).

The most common adverse reactions reported in the clinical trial are summarized in Table 1.

TABLE 1 :Most Common Adverse Reactions*

Elevated tyrosine levels > 10%
Leukopenia 3%
Thrombocytopenia 3%
Conjunctivitis 2%
Corneal opacity 2%
Keratitis 2%
Photophobia 2%
Eye pain 1%
Blepharitis 1%
Cataracts 1%
Granulocytopenia 1%
Epistaxis 1%
Pruritus 1%
Exfoliative dermatitis 1%
Dry skin 1%
Maculopapular rash 1%
Alopecia 1%
*reported in at least 1% of patients

Adverse reactions reported in less than 1% of the patients, included death, seizure, brain tumor, encephalopathy, hyperkinesia, cyanosis, abdominal pain, diarrhea, enanthema, gastrointestinal hemorrhage, melena, elevated hepatic enzymes, liver enlargement, hypoglycemia, septicemia, and bronchitis.

Read the entire FDA prescribing information for Orfadin (Nitisinone)

Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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