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Nulibry Side Effects

Generic name: fosdenopterin

Medically reviewed by Last updated on Sep 9, 2022.

Note: This document contains side effect information about fosdenopterin. Some dosage forms listed on this page may not apply to the brand name Nulibry.

Applies to fosdenopterin: intravenous powder for solution.

Serious side effects of Nulibry

Along with its needed effects, fosdenopterin (the active ingredient contained in Nulibry) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking fosdenopterin:

More common

  • Chills
  • cold flu-like symptoms
  • cough or hoarseness
  • fever
  • increased sensitivity of the skin to sunlight
  • itching
  • redness or other discoloration of the skin
  • severe sunburn
  • skin rash

Less common

  • Agitation
  • body aches or pain
  • chest pain or tightness
  • cough
  • diarrhea
  • earache
  • ear congestion
  • headache
  • loss of appetite
  • loss of voice
  • nausea
  • pale skin
  • rash with flat lesions or small raised lesions on the skin
  • redness or swelling in the ear
  • runny or stuffy nose
  • seizures
  • sneezing
  • sore throat
  • stomach pain
  • swelling of the eye
  • trouble breathing
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting

Other side effects of Nulibry

Some side effects of fosdenopterin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site

For Healthcare Professionals

Applies to fosdenopterin: intravenous powder for injection.


Adverse reactions were assessed in 9 patients; the most reported reaction was catheter-related complications which were reported in 8 patients. Phototoxicity was reported in animals and patients are advised to avoid exposure to sunlight and use sun protection when that is not possible.[Ref]


Catheter-related complications included complication associated with device, catheter site abscess, catheter site discharge, catheter site extravasation, catheter site pain, catheter site infection, catheter site inflammation, device dislocation, device leakage, device occlusion, and vascular device infection. Catheter-related complications occurred in 8 of 9 patients evaluated for adverse-reactions.

Very common (10% or more): Catheter-related complications (89%)


Very common (10% or more): Pneumonia (44%), coughing/sneezing (44%), upper viral respiratory infection (33%), lower respiratory tract infection (22%), viral tonsillitis (22%)

Nervous system

Very common (10% or more): Seizure (22%)


Very common (10% or more): Rash maculo-papular (22%)

Frequency not reported: fungal skin infection, eczema


One patient dies of necrotizing enterocolitis.

Very common (10% or more): Vomiting (44%), gastroenteritis (33%), diarrhea (33%), abdominal pain (22%), oropharyngeal pain (22%)

Frequency not reported: Fatal necrotizing enterocolitis, oral candidiasis


Very common (10% or more): Viral infection (56%), bacteremia (33%), influenza (22%)

Frequency not reported: Sepsis, varicella


Very common (10% or more): Eye swelling (22%)


Very common (10% or more): Agitation (22%)


Very common (10% or more): Anemia (22%)


Very common (10% or more): Pyrexia (78%), otitis media (44%)


1. "Product Information. Nulibry (fosdenopterin)." Origin Biosciences Inc (2021):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.