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nitisinone

Orfadin · ATC code A16AX04

Also known as: Nitisinon

Key facts
Active substance
nitisinone
ATC code
A16AX04
Authorisation
centrally authorised across the EU (EMA)
Dosage forms
Orfadin 2 mg hard capsules / Orfadin 5 mg hard capsules / Orfadin 10 mg hard capsules · Orfadin 4 mg/ml oral suspension
Marketing authorisation holder
Swedish Orphan Biovitrum International AB
Information as of
2026-10-29

Key facts

Nitisinone is a competitive inhibitor of 4-hydroxyphenylpyruvate dioxygenase in tyrosine metabolism. It is used in hereditary tyrosinemia type 1 and in alkaptonuria.

What it is used for

  • Hereditary tyrosinemia type 1 (HT-1) in adults and children of any age with confirmed diagnosis, combined with dietary restriction of tyrosine and phenylalanine (Orfadin hard capsules and oral suspension).
  • Alkaptonuria (AKU) in adults.

Dosing

  • HT-1: initial dose 1 mg/kg body weight daily, started as early as possible; with body weight < 20 kg divide into two daily doses.
  • HT-1: if urine succinylacetone is still detectable after one month, increase to 1.5 mg/kg/day; 2 mg/kg/day is the maximal dose. If response is satisfactory, adjust only for weight gain.
  • AKU: 10 mg once daily in adults; not studied in children.
  • Capsules can be opened and suspended in a little water or formula diet; the oral suspension (4 mg/ml) suits children and patients who have difficulty swallowing.
  • No specific dose recommendations for the elderly or renal/hepatic impairment.

Contraindications

  • Hypersensitivity to the active substance or any of the excipients.
  • Mothers receiving nitisinone must not breast-feed.

Important warnings

  • Monitoring visits every 6 months; slit-lamp eye examination before starting and at least once a year, with prompt ophthalmology review for visual disorders.
  • Monitor plasma tyrosine: stricter diet if above 500 micromol/l; in HT-1 do not lower tyrosine by reducing nitisinone.
  • HT-1: monitor liver function, liver imaging and alpha-fetoprotein regularly (possible sign of liver malignancy).
  • Monitor platelet and white blood cell counts regularly.
  • AKU: stop temporarily if keratopathy develops.

Side effects

  • By its mode of action, tyrosine rises in all patients; eye reactions (conjunctivitis, corneal opacity, keratitis, photophobia, eye pain) are therefore common.
  • HT-1, common: thrombocytopenia, leucopenia, granulocytopenia; uncommon: exfoliative dermatitis.
  • AKU, very common: keratopathy; common: bronchitis, pneumonia.

Interactions

  • Metabolised by CYP3A4; dose adjustment may be needed with inhibitors or inducers.
  • Moderate CYP2C9 inhibitor: may raise levels of CYP2C9 substrates; weak inhibitor of OAT1 and OAT3.

Pregnancy and breastfeeding

  • Use in pregnancy only if the woman's condition requires it; nitisinone crosses the placenta.
  • Breast-feeding is contraindicated.

Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

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For patients

Package leaflet, verbatim

This product has no separate US patient information.

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

EU – centrally authorised (all member states)

  • Nityr · genericCycle Pharmaceuticals (Europe) Ltd · EMEA/H/C/004582
  • OrfadinSwedish Orphan Biovitrum International AB · EMEA/H/C/000555

Source: European Medicines Agency (EMA), product information

Austria

  • Nitisinon DipharmaDipharma Arzneimittel Gmbh · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Germany

  • Nitisinone DipharmaDipharma Arzneimittel Gmbh · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Turkey

  • TisinonNOBEL İLAÇ SAN. VE TİC. A.Ş. · 4 register entries

Source: TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, as of 2026-10-16

Brand names in 15 more European countries
Belgium
Nitisinone Dipharma
Bulgaria
Тисинон
Denmark
Nitisinone Dipharma
Finland
Nitisinone Dipharma
France
Nitisinone Dipharma
Iceland
Orfadin
Ireland
Nitisinone Dipharma
Italy
Nitisinone Dipharma
Liechtenstein
Orfadin
Netherlands
Nitisinone Dipharma
Norway
Nitisinone Dipharma, Orfadin
Portugal
Nitisinona Dipharma
Slovakia
Nitisinone Dipharma
Spain
Nitisinona Dipharma
Sweden
Nitisinone Dipharma

EMA – Article 57 product data (EU/EEA), 2026-10-29

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

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Sources

  1. European Medicines Agency. Orfadin – EPAR, Product Information. 2026-10-29. https://www.ema.europa.eu/en/documents/product-information/orfadin-epar-product-information_en.pdf
  2. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  3. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  4. TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, 2026-10-16. https://www.titck.gov.tr/dinamikmodul/85

Editorial: Medelix editorial team · last updated 2026-10-29 · How these pages are made · Report an error

Source: European Medicines Agency (EMA), product information. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.