Idursulfase (Intravenous)


In the US, idursulfase is also known under the brand name Elaprase. It is a prescription-only medicine that is given intravenously, usually in a clinic, in hospital or by your doctor.

Idursulfase is the preferred medication to treat a rare genetic condition called Hunter syndrome, also known as mucopolysaccharidosis. Hunter syndrome is caused by a shortage of the enzymes that the body uses to metabolize certain proteins and sugars. This leads to an accumulation of these substances in the body, causing abnormal bone structure, enlarged organs, breathing difficulties, altered facial feature, visual impairment, heart problems and changes in physical and cognitive abilities.

Many patients find that taking idursulfase helps to improve their mobility. It should be noted that this medication will not provide a cure for Hunter syndrome.

While you are using idursulfase, your doctor may place your name on a Hunter Outcome Survey. This registry is used by researchers into the condition to monitor the effects that this drug has on the long-term treatment of patients with Hunter syndrome.

Idursulfase may also be used to treat certain other conditions or for other purposes that are not mentioned in this specific guide.

Conditions Treated

  • Hunter syndrome

Type Of Medicine

  • Solution for intravenous injection

Side Effects

Together with the effects it is designed to have, idursulfase can also cause some unwanted side effects in some patients. You may not experience all these effects, but if you do, they may need further medical treatment.

If you notice any of the side effects listed below, notify your nurse or treating physician right away:

  • Weight gain
  • Feeling unusually tired or weak
  • Losing consciousness
  • Tightness in the chest
  • Sweating
  • Sore throat
  • Sneezing
  • Reddening of the skin
  • Redness of the neck, face, upper chest, and arms
  • Rash
  • Swelling or puffiness around the eyes, the eyelids, face, tongue, or lips
  • No pulse or blood pressure
  • No breathing
  • Itching
  • Irregular breathing
  • Welts or hives
  • Cardiac arrest
  • Headache
  • Fever
  • Feelings of warmth
  • Rapid, pounding, or irregular pulse or heartbeat
  • Extreme fatigue
  • Feelings of dizziness, lightheadedness, or faintness when rising suddenly from a prone or seated position
  • Dilated neck veins
  • Difficulty with swallowing
  • Cough
  • Confusion
  • Chills
  • Chest pains
  • Bone or muscle pains
  • Blurred or disturbed vision

There are some side effects that are caused by idursulfase that do not generally require further medical help. These effects usually vanish during the course of your treatment as your body gets used to the new drug. In addition, your treating physician may also be able to advise you on ways in which you can prevent or reduce some or all of the unwanted effects.

Ask your doctor for advice if any of the following effects are slow to resolve, are especially troublesome, or if you have any other questions on your medication:

  • Alterations in hearing
  • Diarrhea
  • Ear drainage
  • Pain in the ears or earache
  • Nausea
  • Vomiting

The side effects mentioned in this guide may not necessarily be an all-inclusive list. If you notice any other odd reactions or effects, check with your doctor right away.


You will usually be give idursulfase by a suitably trained medical professional in a hospital or clinic setting.

The drug is administered through a needle that will be put into one of your veins via a cannula. You will usually receive idursulfase once weekly as an infusion. This means that the medication will be slowly dripped into your vein over a duration of a few hours. Your treating physician may also give you other drugs in order to prevent any allergic reactions that you may experience to the drug.


Drug interactions

There are some drugs that should never be used together under any circumstances, as to do so could cause a dangerous interaction between them. However, in other cases where using two or more drugs at the same time is deemed to be the best course of treatment for your condition, your doctor may decide to change the dose or frequency of use of one or both of the medicines.

Be sure to tell your treating physician if you are currently using any other prescription or over the counter medications, including herbal remedies and vitamin supplements.

Other interactions

Some medications should not be taken when you are eating or when eating particular good groups, as this can trigger an interaction. Consuming alcohol or using tobacco with certain drugs can also cause an interaction. Be sure to talk to your treating physician about this aspect of your treatment with idursulfase.

Medical interactions

There are some existing or historical health conditions that can affect the way in which idursulfase works. You must tell your doctor about any other medical issues that you have before you start treatment with this drug, especially those outlined below.

Idursulfase should be used with caution in patients with the following conditions, as this drug could present a heightened risk of you developing potentially fatal complications:

  • Fluid overload
  • Heart disease
  • Illness that causes fever
  • Breathing difficulties or respiratory diseases


Before you make the decision to undergo treatment with idursulfase, you must consider its benefits against the potential risks of doing so. This decision can be made following discussions with your treating physician, but the following implications of using this medicine should be considered:


Be sure to tell your treating physician if you have ever experienced any unusual reactions to idursulfase in the past. Also mention any known allergies that you have to particular food groups, food colors, preservatives or animal derivative products. Ask to see the product label for this drug so that you can check the components for any potential allergens.


To date, there have been no specific studies into the effect of idursulfase on children under 16 months of age. However, it has been established that the use of this drug is useful and safe in children over this age. If you have any concerns in this regard, speak with your child's doctor.


There has been no research specifically geared towards the use of idursulfase in elderly patients. However, there is nothing to suggest that its use in patients in this age demographic may not be safe and effective.

Pregnancy and breastfeeding

According to FDA pregnancy category 'C', idursulfase can present a risk to the fetus. Pregnant women should, therefore, inform their doctor of their condition before they begin using this drug. You should also tell your treating physician if you are intending to become pregnant while treatment is in progress.

Although it is unknown whether this drug can be ingested by a nursing infant, you should tell your doctor if you are breastfeeding. Ask your doctor or midwife for guidance on alternative feeding options for your infant until you have finished using idursulfase. Do not express breast milk for later use.

Medical complications

You must attend your treating physician for regular progress checks throughout the course of your treatment with idursulfase. These visits will enable your medical professional to monitor your progress and check for any unwanted side effects that the drug may be causing.

Patients should note that idursulfase can sometimes cause serious allergic effects in some people, including a potentially life-threatening condition called anaphylaxis. If you notice any of the following effects immediately after receiving treatment with this drug, you must get emergency medical attention right away:

  • Rash
  • Breathing difficulties
  • Itching
  • Trouble swallowing
  • Swelling of the mouth, tongue, face, throat, or hands


You will usually receive treatment with idursulfase in a hospital or clinic setting, so there will be no need for you to store this drug in your home. However, if home treatment is recommended in your case, your treating physician or nurse will tell you how to store your prescription safely and correctly.


Idursulfase is a prescription-only, intravenous drug that is used to treat a rare genetic condition called Hunter syndrome, (mucopolysaccharidosis).

The condition occurs when the body is starved of a particular enzyme that metabolizes certain proteins and sugars. The consequent accumulation of these substances in the body leads to a number of problems, including respiratory issues and changes in physical and cognitive abilities.

Idursulfase is very effective in improving patients' mobility. However, it should be noted by Hunter patients that this medication will not provide a cure for the condition.

Patients receiving idursulfase may be placed on a Hunter Outcome Survey. This registry is being developed to aid research into the condition and to assess what effects this drug can have on the long-term treatment of the condition.

Although there are no recorded drug interactions for this medicine, it can cause serious side effects in patients with certain pre-existing conditions. For this reason, you should discuss your medical history fully with your doctor before you start treatment with idursulfase.

Note that this drug can be harmful to the unborn baby. Tell your treating physician if you are pregnant or if you are intending to become so during the course of your treatment.