NITISINONE
Background and Date of Approval
Nitisinone is an enzyme inhibitor that blocks 4-hydroxyphenylpyruvate dioxygenase. It is primarily used to treat hereditary tyrosinemia type 1 (HT-1), a rare inherited metabolic disorder. Nitisinone received its initial FDA approval in the United States in 1992 for the treatment of HT-1. Its use in alkaptonuria is a separate clinical application and should be described according to the specific formulation and regulatory approval.
Uses
This medicine is used to treat a rare disease called hereditary tyrosinemia type 1 (adults, adolescents, and children of all ages) and alkaptonuria (adults). It works by blocking the breakdown of the amino acid tyrosine and preventing the accumulation of harmful substances.
How is it administered?
Take the Nitisinone as your physician advises. Usually, this capsule will be taken once a day. Do not crush, chew, or open the medicine. Your physician will decide the correct dosage and duration based on age, body weight, and disease condition. Only stop taking the capsule if your doctor advises you to stop.
Side Effects
The most common side effects of Nitisinone are elevated levels of tyrosine, reduced platelet count, decreased lymphocyte count, conjunctivitis (eye inflammation), corneal opacity (clouding of the cornea), photophobia (sensitivity to light), eye irritation (keratopathy), eyelid inflammation, cataract (clouding of the eye's lens), reduced granulocyte count, itching.
Warnings
Nitisinone should not be consumed if you are allergic to Nitisinone or any of its ingredients in the medication. Before taking this medicine, it is important to consult with your doctor. Inform your doctor if you have or have a history of any liver or kidney conditions. Notify your doctor if you have leukopenia (reduced WBC in the blood) or thrombocytopenia (reduced plated count in the blood). Your doctor will monitor platelet and white blood cell counts before initiating the treatment.
Precautions
During the treatment, regular eye examinations will be conducted to monitor for any potential effects on the eyes. Blood samples will be taken to assess the treatment's effectiveness and detect any possible blood disorders. Regular liver check-ups will be performed if you receive Nitisinone for hereditary tyrosinemia type 1. Follow-up appointments with your doctor every six months are recommended, and shorter intervals may be necessary if you experience any side effects.
Word of Advice
Continue taking Nitisinone exactly as your doctor has directed. Do not increase the dose to make up for a missed dose. Patients with liver or kidney disease should use Nitisinone with caution and inform their doctor of all existing medical conditions. Dose adjustments will be determined based on age, weight, and underlying medical conditions. Avoid breastfeeding while taking Nitisinone. Inform your doctor if you experience any serious side effects. Speak with your doctor for additional information.
References
LogixX Pharma Ltd, Electronic Medicines Compendium (EMC), [Revised on December 2022] [Accessed on 1st June 2023], pil.14734.pdf (medicines.org.uk) Apotek Produktion & Laboratorier, US Food and Drug Administration, [ Revised on November 2021] [ Accessed on 1st June 2023], https://www.orfadin.com/pdf/full-prescribing-information.pdf European medicines agency, [ Accessed on 1st June 2023], Orfadin | European Medicines Agency (europa.eu)
Frequently Asked Questions
How to manage the side effects of Nitisinone?
To manage the side effects of Nitisinone, follow the prescribed dosage, and report side effects promptly. Stay hydrated, and monitor blood pressure regularly. Maintain a healthy lifestyle, and attend follow-up appointments.
Can Nitisinone cause vision problems?
Nitisinone may cause vision problems as a side effect, including other visual disturbances, pain, irritation, and inflammation. If you experience any changes in your eye while taking Nitisinone, notify your doctor immediately.
Can you take Nitisinone when pregnant?
Consult your medical professional regarding the use of Nitisinone during pregnancy. The potential benefits and risks should be carefully assessed. Your doctor will suggest taking this medicine only if it's necessary.
What are the side effects of Nitisinone?
Common side effects of Nitisinone include elevated levels of tyrosine, reduced platelet count, decreased lymphocyte count, conjunctivitis (eye inflammation), corneal opacity (clouding of the cornea), and other visual problems. It is mandatory to consult your doctor for any concerns or persistent side effects.
What should I do if I miss a dose of Nitisinone?
If you miss a capsule dose, take it as soon as possible. However, if it's close to the time for your next dose, skip the missed dose and continue with your regular schedule. Do not double the dose the Nitisinone.