fosdenopterin

Provides an external source of cyclic pyranopterin monophosphate, which is deficient in molybdenum confactor deficiency type A. Cyclic pyranopterin monophosphate is ultimately converted to molybdenum cofactor, which is needed for the activation of various enzymes, including sulfite oxidase, which reduces levels of neurotoxic sulfites.

Therapeutic effects:

Improved survival.

Pharmacokinetics ⬆ ⬇

Absorption: IV administration results in complete bioavailability.

Distribution: Extensively distributed to tissues.

Metabolism/Excretion: Primarily metabolized via nonenzymatic degradation processes to compound Z, an inactive oxidation product of endogenous cyclic pyranopterin monophosphate. Renal excretion accounts for 40% of total body clearance.

Half-Life: 1.2–1.7 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
IV	rapid	end of infusion	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

None.

Use Cautiously in:

OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding.

Adv. Reactions/Side Effects ⬆ ⬇

Derm: photosensitivity, rash

EENT: eye swelling, oropharyngeal pain, sneezing

GI: abdominal pain, diarrhea, vomiting

Hemat: anemia

Neuro: agitation, seizures

Resp: cough

Misc: catheter-related complications, fever, infection

Interactions ⬆ ⬇

Drug-drug:

None reported.

Route/Dosage ⬆ ⬇

IV (Adults and Children ≥1 yr): 0.9 mg/kg (actual body weight) once daily.
IV (Children ≥37 wk [gestational age]–<1 yr): 0.55 mg/kg (actual body weight) once daily for 1 mo; then ↑ to 0.75 mg/kg (actual body weight) once daily for 2 mo; then ↑ to target dose of 0.9 mg/kg (actual body weight) once daily.
IV (Children <37 wk [gestational age]): 0.4 mg/kg (actual body weight) once daily for 1 mo; then ↑ to 0.7 mg/kg (actual body weight) once daily for 2 mo; then ↑ to target dose of 0.9 mg/kg (actual body weight) once daily.

Availability ⬆ ⬇

Lyophilized powder for injection: 9.5 mg/vial

Assessment ⬆ ⬇

Monitor for signs of infection (fever, bacteremia, shortness of breath, otitis media); treat as clinically indicated.
Monitor for signs of gastroenteritis (fever, vomiting, diarrhea, abdominal pain); treat as clinically indicated.

Lab Test Considerations:

Confirm molybdenum cofactor deficiency type A diagnosis with genetic testing immediately after therapy initiation; discontinue fosdenopterin if diagnosis not confirmed.

Implementation ⬆ ⬇

Intended to be administered by health care professional or at home by patient/caregiver if deemed appropriate.

IV Administration:

Y-Site Incompatibility:
- Do not administer other drugs through same IV line.

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication to patient. Advise patient to read Patient Information before starting therapy.
Instruct patient in correct technique for home infusion, care, and disposal of equipment as indicated.
Advise patient to administer missed dose as soon as remembered, and schedule the next dose ≥6 hr after missed dose is administered.
Advise patient to avoid or minimize exposure to direct sunlight and artificial UV light by wearing protective clothing, hat, sunglasses, and broad-spectrum sunscreen with high protection factor (if ≥6 mo of age).
Advise patient to notify health care professional if symptoms of gastritis (fever, vomiting, diarrhea, abdominal pain, dehydration) occur.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other medications.
Rep: Advise women of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇