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Nityr Side Effects

Generic Name: nitisinone

Note: This document contains side effect information about nitisinone. Some of the dosage forms listed on this page may not apply to the brand name Nityr.

For the Consumer

Applies to nitisinone: oral capsule, oral suspension, oral tablet

Along with its needed effects, nitisinone (the active ingredient contained in Nityr) 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 your doctor immediately if any of the following side effects occur while taking nitisinone:

Less common
  • Black, tarry stools
  • bleeding gums
  • blindness
  • blood in the urine or stools
  • bloody nose
  • blurred vision
  • burning, dry, or itching eyes
  • change in color vision
  • chest pain or discomfort
  • chills
  • cough
  • decreased vision
  • difficulty seeing at night
  • excessive eye tearing
  • eye redness, irritation, or pain
  • fever
  • increased sensitivity of the eyes to sunlight
  • painful or difficult urination
  • pinpoint red spots on the skin
  • redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • swollen or painful glands
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • Agitation
  • back pain
  • bluish color of the fingernails, lips, skin, palms, or nail beds
  • confusion
  • cough with mucus
  • difficulty with breathing
  • dizziness
  • drowsiness
  • hallucinations
  • headache
  • irritability
  • seizures
  • stiff neck
  • tightness in the chest
  • vomiting

Some side effects of nitisinone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common Rare

For Healthcare Professionals

Applies to nitisinone: oral capsule, oral suspension, oral tablet


The most common reported side effects included hepatic neoplasm, liver failure, thrombocytopenia, leucopenia, visual system complaints (conjunctivitis, corneal opacity, keratitis, photophobia).[Ref]


Uncommon (0.1% to 1%): Pruritis (1%), exfoliative dermatitis (1%), dry skin (1%), maculopapular rash (1%), alopecia (1%)[Ref]


Frequency not reported: Hypoglycemia[Ref]


Frequency not reported: Abdominal pain, diarrhea, enanthema, gastritis, gastroenteritis, gastrointestinal hemorrhage, melena, tooth discoloration[Ref]


Frequency not reported: Amenorrhea[Ref]


Common (1% to 10%): Thrombocytopenia (3%), leucopenia (3%), granulocytopenia (1%), porphyria (1%), epistaxis (1%)[Ref]


Common (1% to 10%): Liver failure (7%)
Frequency not reported: Hepatic function disorder, elevated hepatic enzymes, liver enlargement[Ref]


Frequency not reported: High plasma tyrosine levels, dehydration[Ref]


Frequency not reported: Pathological fracture[Ref]

Nervous system

Frequency not reported: Seizures, brain tumor, encephalopathy, headache, hyperkinesia, nervousness, somnolence[Ref]


Common (1% to 10%): Conjunctivitis (2%), corneal opacity (2%), keratitis (2%), photophobia (2%), blepharitis (1%), eye pain (1%), cataracts (1%)[Ref]


Common (1% to 10%): Hepatic neoplasm (8%)[Ref]


Frequency not reported: Death, cyanosis, thirst, infection, septicemia, otitis[Ref]


Frequency not reported: Bronchitis, respiratory insufficiency[Ref]


1. "Product Information. Orfadin (nitisinone)." Orphan Pharmaceuticals USA, Inc, Nashville, TN.

Some side effects of Nityr may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.