How does this medication work? What will it do for me?

Laronidase is used to treat mucopolysaccharidosis I (MPS I), a genetic disorder where the body does not have enough of an enzyme called alpha-L-iduronidase. Without this enzyme, substances called glycosaminoglycans (GAGs) build up in the body, causing tissue and organ damage.

Laronidase works by replacing the missing enzyme, which helps the body break down GAGs - a process known as enzyme replacement therapy (ERT). Laronidase is used to treat the symptoms of MPS I that occur in parts of the body other than the brain and spinal cord.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are being given this medication, speak to your doctor. Do not stop receiving this medication without consulting your doctor.

What form(s) does this medication come in?

Each mL of sterile, colourless-to-pale-yellow, clear to slightly opalescent solution contains 0.58 mg of laronidase. The vial does not contain preservatives. Nonmedicinal ingredients: polysorbate 80, sodium chloride, sodium phosphate monobasic monohydrate, sodium phosphate dibasic heptahydrate, and water for injection.

How should I use this medication?

The recommended dose is 0.58 mg per kilogram of body weight given once per week. Laronidase is given by intravenous (into a vein) infusion over a period of 3 to 4 hours in a clinic or hospital setting. An experienced doctor must supervise the treatment. You should keep all your appointments and follow-ups as recommended by your doctor.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are receiving the medication without consulting your doctor.

It is important to receive this medication exactly as recommended by your doctor. If you miss an appointment to receive laronidase, contact your doctor as soon as possible to reschedule your appointment.

This medication is stored in the refrigerator. It should not be shaken or allowed to freeze.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Laronidase should not be used by anyone who is allergic to laronidase or to any of the ingredients of the medication.

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • back pain
  • infusion reactions (e.g., chills, flushing, fever, headache, rash)
  • injection site reaction (e.g., irritation, redness, or itching at the place where the medication was injected)
  • joint pain
  • rash
  • upper respiratory tract infection

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • chest pain
  • dizziness
  • fast heart rate
  • increased blood pressure
  • overactive reflexes
  • swelling of the feet or ankles
  • unusual prickling, tingling, or burning sensations

Seek immediate medical attention if any of the following occur:

  • symptoms of a severe allergic reaction (e.g., hives, swelling of face or throat, or difficulty breathing, wheezing)

Some people may experience side effects other than those listed. Check with your doctor or pharmacist if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.


Nov. 25, 2009

Health Canada has issued new restrictions concerning the use of Aldurazyme® (laronidase). To read the full Health Canada Advisory, visit Health Canada's web site at

Kidney or liver function: The safety and effectiveness of this medication are not known in people with reduced kidney or liver function. People with reduced kidney or liver function should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Premedication: Most people who receive laronidase will also be given medications (e.g., acetaminophen, diphenhydramine) to reduce infusion-related side effects such as fever, chills, headache, and flushing. These medications are usually given about 60 minutes before laronidase is given.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while receiving this medication, contact your doctor immediately.

Breast-feeding: It is not known if laronidase passes into breast milk. If you are a breast-feeding mother and are receiving this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children less than 6 months old.

What other drugs could interact with this medication?

There may be an interaction between laronidase and any of the following:

  • chloroquine
  • procaine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.