Nitisinone
Nitisinone is a medication used to treat hereditary tyrosinemia type 1 (HT-1), a rare genetic disorder in which the body cannot properly break down the amino acid tyrosine due to deficiency of fumarylacetoacetate hydrolase. By inhibiting an enzyme upstream in the tyrosine catabolic pathway, nitisinone prevents the accumulation of toxic metabolites that cause liver and kidney damage in affected patients.
Nitisinone treats hereditary tyrosinemia type 1 by blocking an enzyme in tyrosine metabolism to prevent accumulation of toxic substances.
Key facts at a glance
- ATC
- A16AX04
- RxNorm
- 61805
- Generic
- Nitisinone
- Class
- atc-a16
- Brands
- Nityr, Harliku, Orfadin
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- capsule, tablet, suspension
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Hereditary tyrosinemia type 1 (HT-1), a rare autosomal recessive genetic disorder characterized by deficiency of fumarylacetoacetate hydrolase in the tyrosine degradation pathway.
Nitisinone is a competitive inhibitor of 4-hydroxyphenyl-pyruvate dioxygenase (HPPD), an enzyme upstream of fumarylacetoacetate hydrolase. By blocking HPPD, it prevents the formation and accumulation of toxic tyrosine catabolites, including succinylacetone, that cause hepatic and renal toxicity.
Should be used alongside dietary restriction of tyrosine and phenylalanine. Requires regular monitoring of liver function, AFP levels, and urine succinylacetone. May cause elevated plasma tyrosine levels leading to corneal deposits, photophobia, and developmental delays if not properly managed with diet. Treatment should be initiated as early as possible in infancy.
Official drug label
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This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy