Suitability of Nitisinone in Alkaptonuria 2

Inclusion Criteria: A patient must fulfil the following criteria in order to be included in the study: 1\. Diagnosis of AKU Any Clinical manifestations of AKU, such as clinical ochronosis or chronic back/joint pain. 3\. Age ≥25 years. 4. Willing and able to visit the investigational site for study visits. 5. Signed written informed consent given. \- Exclusion Criteria: The presence of any of the following will exclude a patient from inclusion in the study: 1. Currently pregnant or lactating. 2. Female patient of child-bearing potential not using a reliable method of contraception. 3. Known allergy to nitisinone or any of the constituents of the investigational product. 4. Current malignancy. 5. Uncontrolled hypertension (blood pressure greater than 180 mmHg systolic or greater than 95 mmHg diastolic). 6. Unstable cardiovascular disease. 7. Serum potassium \< 3.0 mmol/L. 8. eGFR \< 60 mL/min . 9. ALT \> 1.5 x upper limit of normal. 10. Haemoglobin \< 10.0 g/dL. 11. Platelets \< 100 x 109/L. 12. Total white blood count \< 3.0 x 109/L or neutrophil count \< 1.5 x 109/L. 13. History of alcohol or drug abuse. 14. Participation in another clinical study within 3 months of randomization. 15. Treatment with nitisinone within 60 days of randomization. 16. Psychiatric or somatic illness that interferes with compliance or communication with health care personnel. 17. Foreseeable inability to cooperate with given instructions or study procedures. 18. Any other medical condition which in the opinion of the investigator makes the patient unsuitable for inclusion. \-