NITYR® (nitisinone) Tablets

What is NITYR?

NITYR is an FDA-approved tablet indicated for the treatment of adult and pediatric patients with Tyrosinemia Type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine. Designed with convenience in mind, NITYR may give patients and their caregivers one less thing to worry about.

At Cycle, we know that supporting people with rare diseases is about more than just the medicine. That’s why we created Cycle Vita, delivering individualized product support with NITYR, every step of the way.

More and more people with Tyrosinemia Type 1 and their caregivers are discovering the independence NITYR can bring to their nitisinone medicine.

NITYR® (nitisinone) Tablets

NITYR product support available to you

Start your NITYR enrollment here

Download and print the enrollment form, share it with your doctor
and discuss why you think NITYR may be suited to your needs.

The first steps

Your Cycle Vita team will quickly get to work with your insurance provider to help you understand your coverage.

We will coordinate seamlessly between different parties, such as insurance companies, doctors, and pharmacists to assist with your prior authorization and documentation requirements.

We will route your NITYR therapy to the appropriate specialty pharmacy and follow-up to ensure swift shipment of your medication.

Additional assistance, when required, throughout your journey

In some cases, an appeal may be needed. Where this is the case, our experienced team will work with your insurer and doctor to understand and overcome any NITYR reimbursement gaps.

If you have commercial insurance, you may be eligible for the Cycle Vita Co-pay Assistance Program. Commercially insured eligible patients may pay as little as $0. Please contact Cycle Vita to find out more about this and other programs that may be available to you (such as the Bridge Program).

The Bridge Program is for eligible* patients with an urgent medical need. This includes new patients, and existing patients who are experiencing a temporary disruption due to insurance changes. Please contact Cycle Vita to find out more about this and other programs that may be available to you (such as Co-pay Assistance).

Important notice

Our proactive team will remind your doctor when your NITYR prescription needs to be renewed, in a timely manner, to ensure an uninterrupted supply of your therapy.

We provide product support to help you manage every aspect of your NITYR therapeutic routine, such as clinical education and 1-to-1 administration training.

Translation services are available on request.

What is Tyrosinemia Type 1 (HT-1)?

Tyrosinemia Type 1 is an inherited autosomal recessive genetic condition. When a person is born with Tyrosinemia Type 1 their body is missing the enzymes to break down the amino acid tyrosine in food. Without this enzyme, a dangerous buildup of toxic substances in the body can occur. This in turn can lead to serious liver and kidney problems, making early diagnosis and management essential.

Following a low protein diet is a key part of living with Tyrosinemia Type 1. Published medical guidelines recommend patients with Tyrosinemia Type 1 follow a low-protein diet to avoid complications associated with elevated plasma tyrosine levels. 1 However, eating properly while following a low-protein diet can be challenging.

As part of the NITYR Experience, eligible patients can utilize the Patient Nutrition Program, which provides access to a Registered Dietitian to support you in following the nutrition goals set and agreed upon by your healthcare team. Please contact Cycle Vita to find out more about this and other programs that may be available to you. 

In the United States, Tyrosinemia Type 1 is primarily diagnosed at birth. Newborn screening typically involves a heel stick blood test. However, a positive screening result may not be definitive. Your healthcare provider will generally order additional blood and urine tests to confirm the diagnosis. Early testing gives the opportunity to start treating you baby as early as possible, minimizing the risk of further complications. 

Remember, you’re not alone. The Cycle Vita team is here to support you for life .



*Some areas of support may not be accessible to all patients. Eligibility criteria may apply to ensure compliance with all applicable federal and state requirements, and benefits may be limited to commercially insured patients only. For more detailed information about eligibility, terms and conditions, please contact the Cycle Vita team at +1 (888) 360-8482.

Cycle Vita™ is a trademark of Cycle Pharmaceuticals in the United States. NITYR® is a registered trademark of Cycle Pharmaceuticals in the United States.


  1. Chinsky JM, Singh R, Ficicioglu C, van Karnebeek CDM, Grompe M, Mitchell G, Waisbren S, Gucsavas-Calikoglu M, Wasserstein MP, Coakley K, Scott CR, Diagnosis and treatment of tyrosinemia type I: a US and Canadian consensus group review and recommendations. Genet Med. 2017 Dec;19(12):1-16. doi: 10.1038/gim.2017.101
Important Safety Information and Indications

NITYR® (nitisinone) Tablets are a competitive inhibitor of 4-hydroxyphenyl-pyruvate dioxygenase indicated for the treatment of adult and pediatric patients with Hereditary Tyrosinemia Type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine.

Do not take NITYR if you are allergic to nitisinone or any other ingredients. Tell your healthcare provider about any health problems, and if you are pregnant or planning to become pregnant and/or breastfeeding, before starting treatment.

Eye Symptoms, Developmental Delay and Skin Changes Due To Elevated Plasma Tyrosine Levels:

Inadequate restriction of tyrosine and phenylalanine intake can result in elevations of plasma tyrosine. Plasma tyrosine levels above 500 micromol/L may lead to ocular signs and symptoms including corneal ulcers, corneal opacities, keratitis, conjunctivitis, eye pain, and photophobia; intellectual disability and developmental delay; or painful hyperkeratotic plaques (thickening of the skin) on the soles and palms.

  • Your healthcare provider should not adjust NITYR dosage in order to lower the levels of tyrosine in the blood.
  • Your healthcare provider will obtain a slit-lamp examination prior to initiating NITYR treatment, regularly during treatment and may reexamine you if you develop symptoms or if your tyrosine levels are above 500 micromol/L.

Changes in blood profile:

  • You may develop leukopenia (reduction in the number of white blood cells, which form part of the immune system) and severe thrombocytopenia (abnormally low levels of platelets, which help the blood to clot).
  • Your healthcare provider will monitor platelet and white blood cell counts, and will adjust your medication accordingly.

The most common adverse reactions (≥1%) in patients with HT-1 taking nitisinone are elevated tyrosine levels, low platelets (thrombocytopenia) or white cells in the blood (leukopenia), and complaints related to the eyes, including conjunctivitis, corneal opacity, inflammation of the cornea, eye pain, blepharitis, cataracts, granulocytopenia and extreme and extreme sensitivity to light (photophobia), nosebleed (epistaxis), itching (pruritus), skin inflammation (exfoliative dermatitis), rash (maculopapular rash), dry skin and alopecia.

Adverse reactions reported in less than 1% of the patients, included death, seizure, brain tumor, brain disease, excessive restlessness, bluish skin, abdominal pain, diarrhea, rash on mucous membranes such as the mouth, gastrointestinal hemorrhage, black colored stools, elevated liver enzymes, liver enlargement, low blood sugar levels, sepsis, and bronchitis.

Nitisinone can interfere with the effect of other medicines. Tell your healthcare provider or pharmacist if you are taking, have recently taken or might take any other medicines.

Pregnancy: The safety of this medicine has not been studied in pregnancy. Tell your healthcare provider immediately if you become pregnant or planning to become pregnant.
Lactation: The safety of this medicine has not been studied in breastfeeding women. Tell your healthcare provider immediately if you plan to breastfeed.
Pediatric Use: The safety and effectiveness of nitisinone has been established in pediatric patients for the treatment of HT-1 in combination with dietary restriction of tyrosine and phenylalanine. Use of NITYR in pediatric patients is supported by evidence from one open-label, uncontrolled clinical study conducted with another oral formulation of nitisinone in 207 patients with HT-1 ages 0 to 22 years (median age 9 months).
Geriatric Use: Clinical studies of nitisinone did not include any subjects aged 65 and over. No clinical studies of nitisinone have been performed in geriatric patients. Your healthcare provider will adjust the dose based on your requirements.

For more detailed information, please refer to the full prescribing information at

If you get any side effects, talk to your healthcare provider. This includes possible side effects not listed in this brochure. You may also report side effects directly by calling Cycle Pharmaceuticals Ltd at 1-855-831-5413 or FDA at 1-800-FDA-1088 or

This website is for education purposes only. It is not intended to be, and should not be used as, a substitute for medical advice.