Pronunciation:

eye-dur-SUL-fase

Brand Names:

• Elaprase

Dosage Forms:

• Solution

Warnings:

Anaphylactoid reactions, which may be life threatening, have been observed in some patients during idursulfase infusions. Appropriate supportive medical treatment should be readily available during treatment. Biphasic anaphylactic reactions have also been observed with idursulfase, and patients who have experienced anaphylactic reactions may require prolonged observation. Patients with compromised respiratory function or acute respiratory disease may be at risk of serious acute exacerbation of their respiratory compromise due to infusion reactions, and require additional monitoring .

Classifications:

Therapeutic—

Enzyme Replacement

Pharmacologic—

Enzyme

Uses of This Medicine:

Idursulfase is used to treat Hunter syndrome (Mucopolysaccharidosis II, MPS II), a rare condition that is most often seen in males. Hunter syndrome is an inherited disease in which the breakdown of a certain chemical in the body (mucopolysaccharide) is defective due to the lack or absence of an enzyme called iduronate-2-sulfatase .

Idursulfase improves signs and symptoms in patients, especially walking capacity, by replacing the missing enzyme in Hunter syndrome .

This medicine is available only with your doctor's prescription .

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Appropriate studies performed to date have not demonstrated pediatrics-specific problems that would limit the usefulness of idursulfase in children. Safety and efficacy have not been established in children under 5 years of age .

Older adults—

No information is available on the relationship of age to the effects of idursulfase in geriatric patients .

Pregnancy—

Breast-feeding—

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Lung disease—Use with caution. You may have a higher risk of developing life-threatening complications .

Proper Use of This Medicine:

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For Hunter syndrome:
  • For injection dosage form:
    • Adults—Dose will be determined based on body weight. The usual dose is 0.5 milligram (mg) per kilogram (kg) once a week. The dose should be infused over 1 to 3 hours
    • Children—Dose will be determined based on body weight. For children over 5 years of age, the usual dose is 0.5 mg per kg once a week. The dose should be infused over 1 to 3 hours. For children under 5 years of age, use and dose must be determined by your doctor .

Missed dose—

Call your doctor or pharmacist for instructions.

Precautions While Using This Medicine:

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and check you for unwanted effects that may be caused by this medicine .

Some people who have used this medicine developed serious allergic reactions while receiving the medicine. Tell your doctor right away if you start having chest tightness, trouble breathing, dizziness, rash, swelling in your face or hands, blurred vision, or convulsions while you are on this medicine .

Side Effects of This Medicine:

Along with its needed effects, a medicine 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 immediately if any of the following side effects occur:

More Common

Accidental injury

atrial abnormality

blurred vision

chest pain

difficulty in breathing or troubled breathing

dizziness

headache

hives or welts

nervousness

pounding in the ears

redness of skin

skin rash with itching

skin disease

slow or fast heartbeat

superficial injury

swelling at site of application.

Less Common

Anxiety

bluish color of fingernails, lips, skin, palms, or nail beds

chest pain or discomfort

confusion

convulsions

cough or hoarseness

faintness

fast, slow, or irregular heartbeat

fever or chills

irregular, fast or slow, or shallow breathing

large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs

lightheadedness when getting up from a lying or sitting position suddenly

lightheadedness

loss of bladder control

lower back or side pain

muscle spasm or jerking of all extremities

painful or difficult urination

pounding or rapid pulse

shortness of breath

sudden loss of consciousness

sweating

tightness in chest

unusual tiredness or weakness.

Some side effects 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

Accumulation of pus

acid or sour stomach

belching

difficulty in moving

disturbed color perception

double vision

fear, irritability

general feeling of discomfort or illness

halos around lights

heartburn

indigestion

muscle pain, spasms, cramps, or stiffness

night blindness

overbright appearance of lights

pain in arms or legs

pain in joints

stomach discomfort, upset, or pain

swollen, red, tender area of infection

tunnel vision.

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.