orfadin
Orfadin (Nitisinone) is a 4-hydroxyphenyl-pyruvate dioxygenase inhibitor used to treat Tyrosinemias.
Nitisinone · by Swedish Orphan
Key facts
- Active ingredient
- Nitisinone
- Form
- Capsule, Suspension
- Strength
- Nitisinone 4MG/ML
- Type
- Prescription (Rx)
- Brand or generic
- Brand-name
- May treat
- tyrosinemias
- Manufacturer
- Swedish Orphan
- Half-life
- about 54 hours (mean terminal half-life) (how long it stays in your system)
- FDA application
- NDA206356
What is Orfadin?
From the FDA label:ORFADIN contains nitisinone, which is a hydroxyphenyl-pyruvate dioxygenase inhibitor indicated as an adjunct to dietary restriction of tyrosine and phenylalanine in the treatment of hereditary tyrosinemia type 1 (HT-1). Nitisinone occurs as white to yellowish-white, crystalline powder. It is practically insoluble in water, soluble in 2M sodium hydroxide and in methanol, and sparingly soluble in alcohol. Chemically, nitisinone is 2-(2-nitro-4-trifluoromethylbenzoyl) cyclohexane-1,3-dione, and the structural formula is: Capsules: Hard, white-opaque capsule, marked as 2 mg, 5 mg, 10 mg or 20 mg strengths of nitisinone, intended for oral administration. Each capsule contains 2 mg, 5 mg, 10 mg or 20 mg nitisinone, plus pre-gelatinized starch. The capsule shell is gelatin and titanium dioxide and the imprint is an iron oxide. Oral suspension: 4 mg/mL, a white, slightly viscous opaque suspension. The inactive ingredients are hydroxypropyl methylcellulose, glycerol, polysorbate 80, sodium benzoate, citric acid monohydrate, trisodium citrate dihydrate, strawberry aroma (artificial) and purified water. Glycerol: Each mL contains 500 mg. Sodium: Each mL contains 0.7 mg (0.03 mEq). Figure 1
How to use
Orfadin is sold in more than one form (Capsule and Suspension), and each is dosed differently. The instructions below come from the FDA label for application NDA206356 — follow the label that came with the product you were actually prescribed.
Recommended Dosage ( 2.1 ) : The recommended starting dosage is 0.5 mg/kg orally twice daily. In patients 5 years of age and older who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone, the total daily dose may be given once daily. Titrate the dosage based on biochemical and/or clinical response, as described in the full prescribing information. The maximum total daily dosage is 2 mg/kg orally. Preparation and Administration Instructions ( 2.2 ) : For instructions on preparing, measuring and administering the oral suspension, see the full prescribing information. Maintain dietary restriction of tyrosine and phenylalanine Take ORFADIN capsules at least one hour before, or two hours after a meal For patients who have difficulties swallowing capsules and who are intolerant to the oral suspension, the capsules may be opened and the contents suspended in a small amount of water, formula or apple sauce immediately before use. Take ORFADIN oral suspension without regard to meals. 2.1 Dosage Starting Dosage The recommended starting dosage of ORFADIN is 0.5 mg/kg administered orally twice daily. Maintenance Regimen In patients 5 years of age and older who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone, the total daily dose of ORFADIN…
Side effects
Most common adverse reactions (>1%) are elevated tyrosine levels, thrombocytopenia, leukopenia, conjunctivitis, corneal opacity, keratitis, photophobia, eye pain, blepharitis, cataracts, granulocytopenia, epistaxis, pruritus, exfoliative dermatitis, dry skin, maculopapular rash and alopecia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Swedish Orphan Biovitrum at 1-866-773-5274 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. ORFADIN was studied in one open-label, uncontrolled study of 207 patients with HT-1, ages 0 to 22 years at enrollment (median age 9 months), who were diagnosed with HT-1 by the presence of succinylacetone in the urine or plasma. The starting dose of ORFADIN was 0.3 to 0.5 mg/kg twice daily, and the dose was increased in some patients to 1 mg/kg twice daily based on weight, biochemical, and enzyme markers. The recommended starting dosage of ORFADIN is 0.5 mg/kg twice daily [see Dosage and Administration ( 2.1 )] . Median duration of treatment was 22 months (range 0.1 to 80 months). The most serious adverse reactions reported during ORFADIN…
Warnings
Important safety information
Elevated Plasma Tyrosine Levels, Ocular Symptoms, Developmental Delay and Hyperkeratotic Plaques : Inadequate restriction of tyrosine and phenylalanine intake can lead to elevations in plasma tyrosine, which at levels above 500 micromol/L can result in symptoms, intellectual disability and developmental delay or painful hyperkeratotic plaques on the soles and palms; do not adjust ORFADIN dosage in order to lower the plasma tyrosine concentration. Obtain slit-lamp examination prior to treatment, regularly during treatment; Reexamine patients if symptoms develop or tyrosine levels are > 500 micromol/L. Assess plasma tyrosine levels in patients with an abrupt change in neurologic status. ( 5.1 ) Leukopenia and Severe Thrombocytopenia : Monitor platelet and white blood cell counts. ( 5.2 ) Risk of Adverse Reactions Due to Glycerol Content of ORFADIN Oral Suspension : Doses of 20 mL of ORFADIN oral suspension may cause headache, upset stomach and diarrhea due to the glycerol content. Consider switching patients to ORFADIN capsules. ( 5.3 ) 5.1 Elevated Plasma Tyrosine Levels, Ocular Symptoms, Developmental Delay and Hyperkeratotic Plaques Nitisinone is an inhibitor of 4-hydroxyphenyl-pyruvate dioxygenase, an enzyme in the tyrosine metabolic pathway [see Clinical Pharmacology ( 12.1 )] . Therefore, treatment with ORFADIN may cause an increase in plasma tyrosine levels in patients with HT-1. Maintain concomitant reduction in dietary tyrosine and phenylalanine while on ORFADIN treatment. Do not adjust ORFADIN dosage in order to lower the plasma tyrosine concentration. Maintain plasma tyrosine levels below 500 micromol/L. Inadequate restriction of tyrosine and phenylalanine intake can lead to elevations in plasma tyrosine levels and levels greater than 500 micromol/L may lead to the following: Ocular signs and symptoms including corneal ulcers, corneal opacities, keratitis, conjunctivitis, eye pain, and photophobia have been reported in patients treated with ORFADIN [see Adverse Reactions ( 6.1 )] . In a clinical study in a non HT-1 population without dietary restriction and reported tyrosine levels >500 micromol/L both symptomatic and asymptomatic keratopathies have been observed. Therefore, perform a baseline ophthalmologic examination including slit-lamp examination prior to initiating ORFADIN treatment and regularly thereafter. Patients who develop photophobia, eye pain, or signs of inflammation such as redness, swelling, or burning of the eyes or tyrosine levels are > 500 micromol/L during treatment with ORFADIN should undergo slit-lamp reexamination and immediate measurement of the plasma tyrosine concentration. Variable degrees of intellectual disability and developmental delay. In patients treated with ORFADIN who exhibit an abrupt change in neurologic status, perform a clinical laboratory assessment including plasma tyrosine levels. Painful hyperkeratotic plaques on the soles and palms In patients with HT-1 treated with dietary restrictions and ORFADIN who develop elevated plasma tyrosine levels, assess dietary tyrosine and phenylalanine intake. 5.2 Leukopenia and Severe Thrombocytopenia In clinical trials, patients treated with ORFADIN and dietary restriction developed transient leukopenia (3%), thrombocytopenia (3%), or both (1.5%) [see Adverse Reactions ( 6.1 )] . No patients developed infections or bleeding as a result of the episodes of leukopenia and thrombocytopenia. Monitor platelet and white blood cell counts during ORFADIN therapy. 5.3 Risk of Adverse Reactions Due to Glycerol Content of ORFADIN Oral Suspension Oral doses of glycerol of 10 grams or more have been reported to cause headache, upset stomach and diarrhea. ORFADIN oral suspension contains 500 mg/mL of glycerol. Patients receiving more than 20 mL of ORFADIN oral suspension (10 grams glycerol) as a single dose are at increased risk of these adverse reactions. Consider switching patients who are unable to tolerate the oral suspension to ORFADIN capsules.
Who should not take Orfadin
None. None ( 4 )
Overdose — what happens if you take too much
Accidental ingestion of ORFADIN by individuals eating normal diets not restricted in tyrosine and phenylalanine will result in elevated tyrosine levels. In healthy subjects given a single 1 mg/kg dose of nitisinone, the plasma tyrosine level reached a maximum of 1200 micromol/L at 48 to 120 hours after dosing. After a washout period of 14 days, the mean value of plasma tyrosine was still 808 micromol/L. Fasted follow-up samples obtained from volunteers several weeks later showed tyrosine values back to normal. There were no reports of changes in vital signs or laboratory data of any clinical significance. One patient reported sensitivity to sunlight. Hyper-tyrosinemia has been reported with ORFADIN treatment [see Warnings and Precautions ( 5.1 )] .
U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.
Interactions
Nitisinone is a moderate CYP2C9 inhibitor, a weak CYP2E1 inducer and an inhibitor of OAT1/OAT3. Table 2 includes drugs with clinically important drug interactions when administered concomitantly with ORFADIN and instructions for preventing or managing them. Table 2: Clinically Relevant Interactions Affecting Co-Administered Drugs Sensitive CYP2C9 Substrates (e.g., celecoxib, tolbutamide) or CYP2C9 Substrates with a Narrow Therapeutic Index (e.g., phenytoin, warfarin) Clinical Impact Increased exposure of the co-administered drugs metabolized by CYP2C9. [see Clinical Pharmacology ( 12.3 )] Intervention Reduce the dosage of the co-administered drugs metabolized by CYP2C9 drug by half. Additional dosage adjustments may be needed to maintain therapeutic drug concentrations for narrow therapeutic index drugs. See prescribing information for those drugs. OAT1/OAT3 Substrates (e.g., adefovir, ganciclovir, methotrexate) Clinical Impact Increased exposure of the interacting drug [see Clinical Pharmacology ( 12.3 )] Intervention Monitor for potential adverse reactions related to the co-administered drug. CYP2C9 Substrates : Increased systemic exposure of these co-administered drugs; reduce the dosage. Additional dosage adjustments may be needed to maintain therapeutic drug concentrations for narrow therapeutic index drugs. ( 7 ) OAT1/OAT3 Substrates : Increased systemic exposure of these co-administered drugs; monitor for potential adverse reactions. ( 7 )
Storing Orfadin, and how long it keeps
Quoted from this product’s own FDA label. Storage belongs to the product and its device, not to the drug in general — a pen and a tablet of the same medicine are kept completely differently.
- “If not used within 45 days, discard ORFADIN capsules.”
- “If not used within 60 days, discard unused portion.”
- “Alternatively, patients/caregivers may store ORFADIN capsules at room temperature up to 25°C (77°F) for up to 45 days.”
How long does Nitisinone stay in your body?
The elimination half-life of nitisinone is about 54 hours (mean terminal half-life) — the time it takes the body to clear about half of it. As a rule of thumb, a medicine is mostly gone after roughly 4 to 5 half-lives, though this varies from person to person with age and kidney or liver function. This is the terminal (elimination) half-life the ORFADIN label reports for a single dose in healthy male adults — roughly 2 days, which is why once-daily dosing works and why it takes about 2 weeks (steady state within 14 days) for levels to plateau after a change. The label does not describe an active metabolite, and nitisinone is not a prodrug: it is only minimally metabolized (in vitro, minor metabolism possibly via CYP3A4) and renal excretion is minor (about 3% of the dose unchanged in urine). The figure is formulation-specific: the NITYR tablet label reports a mean terminal half-life of 59.3 hours (SD 8.9) in healthy subjects. Populations: the label provides NO pharmacokinetic data in kidney impairment or liver impairment, and states that clinical studies included no subjects 65 or over and that no PK studies were done in geriatric patients (it only advises cautious dose selection in the elderly) — so how the half-life shifts in those groups is not established on the label.
This is general information, not medical advice. It doesn’t tell you when a drug test would read negative (tests detect substances for different, often longer, windows) or when it’s safe to take another dose — ask your pharmacist or prescriber. Source: ORFADIN (nitisinone) capsules/oral suspension — FDA label via DailyMed, §12.3 Pharmacokinetics (Elimination).
Drug class
May treat (source: NIH RxClass)
See how Orfadin ranks — best-rated 4-hydroxyphenyl-pyruvate dioxygenase inhibitor for:
Dosage forms
Capsule and Suspension
The forms currently marketed in the U.S., per the FDA National Drug Code Directory.
Ways to save
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Frequently asked questions
- What does Orfadin treat?
- Orfadin (Nitisinone) may be used to treat tyrosinemias, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
- Is there a coupon or discount for Orfadin?
- pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Orfadin. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
- Who makes Orfadin?
- Orfadin is marketed by Swedish Orphan. You can see Swedish Orphan's full profile, rating, and other products on pharmaranks.
- Is Orfadin a brand-name or generic drug?
- Orfadin is a brand-name product with the active ingredient Nitisinone.
- Is Orfadin available over the counter?
- No. Orfadin is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
- What forms does Orfadin come in?
- Orfadin is currently marketed as capsule and suspension, per the FDA's National Drug Code Directory.
- What class of drug is Orfadin?
- Orfadin is classified as 4-hydroxyphenyl-pyruvate dioxygenase inhibitor, per the FDA's Established Pharmacologic Class.
- Is Orfadin FDA-registered?
- Orfadin is on record with the U.S. FDA under application number NDA206356. You can verify this on its official FDA label.
- Is Orfadin safe?
- There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Orfadin. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
- What are the side effects of Orfadin?
- Orfadin's side effects are taken directly from its FDA label. From the label: Most common adverse reactions (>1%) are elevated tyrosine levels, thrombocytopenia, leukopenia, conjunctivitis, corneal opacity, keratitis, photophobia, eye pain, blepharitis, cataracts, granulocytopenia, epistaxis, pruritus, exfoliative dermatitis, dry skin, maculopapular rash and alopecia.… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.
Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.
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