Orfadin

The active ingredient in Orfadin is nitisinone, which is a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor. HPPD is an enzyme in your body that aids in the breakdown of tyrosine from food. The mechanism of action involves blocking this enzyme to prevent tyrosine from being broken down early in the process and turning into harmful toxins. When used as an adjunct to dietary restriction of tyrosine and phenylalanine, it can be effective in the treatment of hereditary tyrosinemia type 1 (HT-1).

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide, before using Orfadin. However, the following is a synopsis of the general guidelines for the use of Orfadin:

• Orfadin oral suspension can be taken with or without food. Orfadin capsules should be taken at least 1 hour before or 2 hours after a meal.
• If you want your treatment to work, you have to avoid specific foods. Adhere to the diet plan that your physician or nutritionist has developed for you.
• Tyrosine and phenylalanine (including artificial sweeteners like aspartame, Equal, or Nutrasweet) are found in diets high in protein. Special foods have been created to substitute high-protein foods since newborns and kids require protein to grow and thrive.
• Before measuring a dose, shake the liquid oral suspension for at least five seconds. Use a medication dose-measuring tool like an oral syringe (not a kitchen spoon) or the supplied dosing syringe.
• Open the capsule and mix the medication into a teaspoon of water, infant formula, or applesauce if you or your child is unable to swallow it whole. Without chewing, immediately swallow the concoction. Don't put it away until later.
• Monitor plasma and/or urine succinylacetone concentrations, liver function parameters, and alpha-fetoprotein levels.

The most common side effects of Orfadin include:

• Elevated tyrosine levels, which can lead to toxicity to your eyes, skin, and nervous system.
• Blepharitis.
• Cataracts.
• Keratitis, inflammation (redness, irritation) of the cornea.
• Exfoliative dermatitis may occur uncommonly.
• Changes to your vision or blurred vision.
• Granulocytopenia (low levels of granulocytes, a type of white blood cell).
• Eye pain.
• Conjunctivitis (pink eye).
• Corneal opacity (clouding of the cornea, the transparent layer that covers your pupil).
• Photophobia (sensitivity to light).
• Thrombocytopenia (reduced levels of platelets).
• Low white blood cells (leukopenia).
• Pruritus or bronchitis.

Some individuals may experience serious side effects while using Orfadin. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Symptoms of an allergic reaction such as hives, trouble breathing, or swelling of your face, lips, tongue, or throat.
• Developmental delays in children (e.g., sitting up, crawling, walking, talking, etc.).
• The liquid form of nitisinone may contain glycerol and can cause a headache, upset stomach, or diarrhea.
• Unusual bleeding from the mouth, nose, vagina, or rectum, easy bruising, and red or purple pinpoint areas beneath the skin.
• Jaundice (eye or skin yellowing).

These are not all of the possible adverse events of Orfadin. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Orfadin, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including whether you have:

• Medical conditions affecting your eyes.
• Low blood counts, including low platelet or white blood cell counts.

There are no specific contraindications of Orfadin. However, if you are allergic or have any other adverse reactions to the medication, you should avoid taking it.

It usually takes about one week for patients to respond to the medication.

When Orfadin is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

Celecoxib (Celebrex), phenytoin (Dilantin), warfarin (Coumadin), and methotrexate are among the medications that interact with nitisinone.

Orfadin is available in 2 mg, 5 mg, 10 mg, and 20 mg capsules. It is also available as a 4 mg/mL oral suspension.

For the treatment of hereditary tyrosinemia type 1, your body weight determines how much nitisinone you need to take. The usual starting dose of Orfadin is 0.5 mg/kg/day twice daily.

Your doctor may change your dosage in response to side effects and blood levels of specific substances.

Do not freeze the liquid or capsules; instead, keep them in the refrigerator. After using Orfadin liquid for the first time, you may store the medicine at room temperature for up to 60 days.

Swedish Orphan Biovitrum (Sobi) is a pharmaceutical company that manufactures Orfadin.

There are several lower-cost generics of Orfadin available.

The drug nitisinone is marketed under the brand names Nityr and Orfadin, and both are effective in treating HT-1 symptoms.

Consult your doctor before stopping or reducing your dosage of Orfadin. Your disease can get worse, or you might get unintended adverse effects if you abruptly stop taking it.

Talk to your doctor if you are already pregnant or if you have any plans to become pregnant. They will know or recommend what is best for you.

It is not known if Orfadin is found in breast milk during lactation. Talk to your doctor if you are already breastfeeding, or if you have any plans to breastfeed. They will know or recommend what is best for you.