Fosdenopterin Dosage

Medically reviewed by Drugs.com. Last updated on Mar 6, 2025.

Applies to the following strengths: 9.5 mg

Usual Adult Dose for Combined Molybdoflavoprotein Enzyme Deficiency

0.9 mg/kg IV once a day

Comments:

Dosing is based on actual body weight; infuse at a rate of 1.5 mL/min with non-DEHP tubing and a 0.2-micron filter.
Safety and effectiveness for use of this drug in adults with of molybedenum cofactor deficiency (MoCD) Type A have been established based on adequate and well-controlled clinical investigation in pediatric patients.

Use: To reduce the risk of mortality in patients with MoCD Type A.

Usual Pediatric Dose for Combined Molybdoflavoprotein Enzyme Deficiency

Patients less than 1 year: Dosing is based on gestational age

Gestational age less than 37 weeks (preterm neonates):

Initial Dosage: 0.4 mg/kg IV once a day
Dose at one month: 0.7 mg/kg IV once a day
Dose at three months: 0.9 mg/kg IV once a day

Gestational age 37 weeks and above (term neonates):

Initial Dosage: 0.55 mg/kg IV once a day
Dose at one month: 0.75 mg/kg IV once a day
Dose at three months: 0.9 mg/kg IV once a day

Patients 1 year or older: 0.9 mg/kg IV once a day

Comments:

Dosing is based on actual body weight; infuse at a rate of 1.5 mL/min with non-DEHP tubing and a 0.2-micron filter (volumes below 2 mL may require syringe administration through slow intravenous push).
Therapy may be started upon diagnosis or presumptive diagnosis of molybedenum cofactor deficiency (MoCD) Type A; for a presumptive diagnosis, confirm with genetic testing and discontinue this drug if diagnosis is not confirmed.

Use: To reduce the risk of mortality in patients with MoCD Type A.

Renal Dose Adjustments

Use with caution; the effect of renal impairment is unknown

Liver Dose Adjustments

Use with caution; the effect of hepatic impairment is unknown

Precautions

CONTRAINDICATIONS: None

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

Administer via IV infusion at a rate of 1.5 mL/minute once a day; an infusion pump should be used unless the dose volume is below 2 mL; for dose volume less than 2 mL, administer slow IV push with a syringe
Administer using non-DEHP tubing with a 0.2-micron filter
This drug is intended for administration by a healthcare provider, although may be administered at home with proper training and instructions.

Missed dose: If dose is missed, administer as soon as possible; administer next scheduled dose at least 6 hours after the administration of the missed dose

Storage requirements:

Unopened vials should be stored frozen (-13F to 14F [-25C to -10C]) in its original carton to protect from light
Reconstituted solution may be stored at room temperature (59F to 77F [15C to 25C]) or refrigerated (36F to 46F 2C to 8C]) for up to 4 hours including infusion time; if refrigerated allow to come to room temperature as noted below; do not re-freeze

Reconstitution/preparation techniques:

Remove vials from freezer and allow to reach room temperature by hand warning (3 to 5 minutes) or exposing to ambient air (approximately 30 minutes); do not heat
Reconstitute each vial with 5 mL sterile water for injection; gently swirl until powder is completely dissolved; do not shake; reconstituted solution 9.5 mg/5 mL (1.9 mg/mL)

IV compatibility: Do not administer as an infusion with other drugs

Patient advice:

Patients should be instructed to read the US FDA-approved patient labeling (Instructions for Use)
Patients/caregivers should be advised of the potential for photosensitivity reactions and measures to be taken to minimize exposure to sunlight and artificial UV light exposure; if a rash or other symptoms of photosensitivity reactions develop (redness, burning sensation of the skin, blisters), seek medical attention immediately.