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Idursulfase Side Effects

For the Consumer

Applies to idursulfase: intravenous solution

Along with its needed effects, idursulfase 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 idursulfase:

More common
  • Bone or muscle pain
  • chest pain
  • chills
  • cough
  • fast, pounding, or irregular heartbeat or pulse
  • feeling of warmth
  • fever
  • headache
  • hives or welts
  • itching
  • rash
  • redness of the face, neck, arms, and occasionally, upper chest
  • redness of the skin
  • sneezing
  • sore throat
  • tightness in the chest
  • unusual tiredness or weakness
Less common
  • Blurred vision
  • confusion
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • sweating
Incidence not known
  • Difficulty with swallowing
  • dilated neck veins
  • extreme fatigue
  • heart stops
  • irregular breathing
  • no breathing
  • no pulse or blood pressure
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • unconscious
  • weight gain

Some side effects of idursulfase 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
  • Change in hearing
  • diarrhea
  • ear drainage
  • earache or pain in the ear
Less common
  • Nausea
  • vomiting

For Healthcare Professionals

Applies to idursulfase: intravenous solution


The most frequently reported adverse effects in all clinical trials were hypersensitivity reactions and included rash, urticaria, pruritus, flushing, pyrexia, and headache.

The most frequently reported adverse effects following treatment were hypoxia, pyrexia, rash, vomiting, diarrhea, cough, musculoskeletal pain, headache, pruritus, and urticaria.[Ref]


In clinical trials, the most common adverse effects were hypersensitivity reactions and included rash, urticaria, pruritus, flushing, pyrexia, and headache. Most reactions were resolved with slowing the infusion rate or temporarily stopping the infusion, with or without additional treatments including antihistamines and/or corticosteroids prior to or during infusions.[Ref]

Very common (10% or more): Hypersensitivity reaction
Frequency not reported: Anaphylactoid/anaphylactic reaction
Postmarketing reports: Late-emergent anaphylactoid reaction[Ref]


In clinical trials, 32 out of 63 patients 5 years and older tested positive for antidrug antibodies at least 1 time; of the 32 patients, 23 tested positive for antidrug antibodies 3 or more times. The incidence of hypersensitivity reactions was higher in positive antidrug antibody patients than those who tested negative. Out of 32 antidrug antibody positive patients, 13 also tested positive for neutralizing antibodies. There was no clear relationship between presence of either type of antibody and therapeutic response.[Ref]

Very common (10% or more): Antidrug antibody development (50%), neutralizing antibody development (24.3%)[Ref]

Nervous system

Very common (10% or more): Headache (up to 65.6%)
Common (1% to 10%): Dizziness, tremor[Ref]


Very common (10% or more): Rash (up to 34.4%), pruritus (up to 31.3%), urticaria (up to 16%)
Common (1% to 10%): Erythema[Ref]


Very common (10% or more): Infusion-related reaction (68.8%), pyrexia (up to 62.5%), chest pain (up to 15.6%), infusion site swelling (12.5%)
Common (1% to 10%): Face edema, peripheral edema[Ref]

The most serious infusion-related reactions included anaphylactoid/anaphylactic reactions. The most common infusion-related reactions included cutaneous reactions (rash, pruritus, urticaria), pyrexia, headache, hypertension, flushing, wheezing, hypoxia, dyspnea, abdominal pain, nausea, dyspepsia, chest pain, and infusion site swelling. Treatment/amelioration of infusion-related reactions included slowing the infusion rate, interrupting the infusion, or drug therapy (e.g., antihistamines, antipyretics, low-dose corticosteroids [prednisone, methylprednisolone], beta-agonist nebulization).[Ref]


Very common (10% or more): Musculoskeletal pain (13%)
Common (1% to 10%): Arthralgia[Ref]


Very common (10% or more): Abdominal pain (up to 53.1%), nausea (up to 28.1%), dyspepsia (12.5%), vomiting, diarrhea
Common (1% to 10%): Swollen tongue[Ref]


Very common (10% or more): Hypertension (up to 25%), flushing (15.6%)
Common (1% to 10%): Cyanosis, arrhythmia, tachycardia, hypotension
Postmarketing reports: Cardiac failure, cardiorespiratory arrest[Ref]


Very common (10% or more): Wheezing (15.6%), dyspnea (up to 12.5%)
Common (1% to 10%): Cough, bronchospasm, tachypnea, hypoxia
Frequency not reported: Pulmonary embolism
Postmarketing reports: Respiratory failure, respiratory distress, pneumonia[Ref]


1. Cerner Multum, Inc. "Australian Product Information." O 0

2. "Product Information. Elaprase (idursulfase)." Shire US Inc, Florence, KY.

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Some side effects of idursulfase may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

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