Laronidase
Laronidase (Aldurazyme) is an enzyme replacement therapy given by IV infusion to treat Mucopolysaccharidosis I (MPS I), a rare inherited enzyme deficiency.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Laronidase (Aldurazyme) is a specialist enzyme replacement given weekly by IV (into a vein) for MPS I, a rare inherited condition (Hurler, Hurler-Scheie, and moderate to severe Scheie forms). It replaces the missing enzyme so cells can break down built-up sugar chains called GAGs, and it has been the standard enzyme treatment since about 2003. Most people tolerate the infusions, but infusion reactions such as fever, chills and flushing are common, along with rash and headache. Its boxed warning covers severe allergic reactions, including anaphylaxis, and sudden breathing complications, so report wheezing, trouble breathing, hives or swelling during an infusion or up to 3 hours after.
Clinical pearls
- Tell the infusion team before your visit about any fever, cold or chest infection, since the infusion may be delayed.
- If you use CPAP or night-time oxygen for sleep apnea, bring it to infusions when your team asks.
- If an infusion is missed, reschedule it as soon as possible and keep the weekly rhythm, never doubling up.
- It has not been shown to help the brain and nervous system symptoms of MPS I, so other care continues.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Aldurazyme can cause life-threatening allergic reactions, including anaphylaxis. It must be given where medical monitoring and emergency resuscitation equipment are ready. If a severe reaction occurs, the infusion is stopped immediately and treated.
People with weak lung function or acute respiratory illness are at risk of serious breathing problems from infusion reactions and need extra monitoring and respiratory support. Watch for trouble breathing, wheezing, hives, swelling, or dizziness.
Patient information guide A plain-language walkthrough of Laronidase, written from its FDA label.
What Laronidase is used for
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Laronidase is used to treat MPS I. Aldurazyme is used for:
- Hurler and Hurler-Scheie forms of MPS I in adults and children
- The Scheie form of MPS I in patients with moderate to severe symptoms
Its use in mildly affected Scheie patients has not been established, and its effect on nervous system symptoms is unknown.
How Laronidase works
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MPS I is caused by a missing enzyme, α-L-iduronidase. Without it, GAG substances (dermatan sulfate and heparan sulfate) build up throughout the body and damage cells, tissues and organs.
Laronidase supplies the missing enzyme. Cells take it in, most likely through mannose-6-phosphate receptors, and it helps break down the GAGs. Whether it reaches the brain has not been studied.
Laronidase dosage
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Aldurazyme is given by IV infusion once a week, usually over about 3 to 4 hours. The dose is based on body weight, and the drug is diluted in saline first.
- Antihistamines (with or without a fever reducer) may be given about an hour beforehand.
- If reactions occur, the infusion may be slowed or paused.
- If you miss a dose, restart as soon as possible and keep the weekly schedule. Do not double up.
Food instructions are not given for this IV drug. Follow your prescriber and label.
Dosing details from the FDA-approved label
From the Laronidase prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Recommended dosage (ALDURAZYME)
- 0.58 mg/kg (actual body weight) administered once weekly as an intravenous infusion
- Dilute with 0.9% Sodium Chloride Injection to a final volume of 50 mL (body weight 2 kg to less than 4 kg), 100 mL (4 kg up to 20 kg) or 250 mL (greater than 20 kg)
- Patients with underlying cardiac or respiratory compromise and weighing up to 30 kg
- Physicians may consider diluting ALDURAZYME in a volume of 100 mL and administering at a decreased infusion rate
- Based on cardiac or respiratory compromise and weight up to 30 kg
- Infusion rate
- Initial infusion rate 10 mcg/kg/hr, may be increased every 15 minutes during the first hour, as tolerated
- Maximum rate maintained for the remainder of the infusion (2 to 3 hours)
- Maximum: 200 mcg/kg/hr
- Total volume administered over approximately 3 to 4 hours as tolerated
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION For pretreatment recommendations, see Full Prescribing Information. ( 2.1 ) The recommended dosage is 0.58 mg/kg administered once weekly as an intravenous infusion. ( 2.2 ) For dosage and administration modifications due to hypersensitivity reactions or infusion-associated reactions (IARs), see Full Prescribing Information. ( 2.3 ) For instructions on preparation, storage, and administration, see Full Prescribing Information. ( 2.4 , 2.5 , 2.6 ) 2.1 Recommendations Prior to ALDURAZYME Treatment Premedication Prior to ALDURAZYME administration, consider premedicating with antihistamines, with or without antipyretics, 60 minutes before the start of infusion [see Warnings and Precautions (5.1 , 5.4) ]. Medical Support Appropriate medical monitoring and support measures, including cardiopulmonary resuscitation equipment, should be readily available during ALDURAZYME administration. 2.2 Recommended Dosage and Administration The recommended dosage of ALDURAZYME is 0.58 mg/kg (actual body weight) administered once weekly as an intravenous infusion. ALDURAZYME injection must be diluted with 0.9% Sodium Chloride Injection to a final volume of 50 mL, 100 mL or 250 mL as determined by the patient's body weight and cardiopulmonary condition: Patients with a body weight equal to or greater than 2 kg and less than 4 kg should receive a total volume of 50 mL; patients with a body weight equal to or greater than 4 kg and up to 20 kg should receive a total volume of 100 mL; and those patients with a body weight greater than 20 kg should receive a total volume of 250 mL [see Dosage and Administration (2.6) ]. For patients with underlying cardiac or respiratory compromise and weighing up to 30 kg, physicians may consider diluting ALDURAZYME in a volume of 100 mL and administering at a decreased infusion rate [see Dosage and Administration (2.6) ]. The initial infusion rate of ALDURAZYME is 10 mcg/kg/hr and may be increased every 15 minutes during the first hour, as tolerated, to a maximum infusion rate of 200 mcg/kg/hr. The maximum rate is then maintained for the remainder of the infusion (2 to 3 hours) [see Dosage and Administration (2.6) , Warnings and Precautions (5.2 , 5.3) ] . If one or more doses are missed, restart ALDURAZYME treatment as soon as possible and maintain the 1-week interval between infusions thereafter.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Laronidase side effects
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The most common side effects are infusion reactions, which tend to become less frequent over time.
Common side effects
- Infusion reactions (fever, chills, flushing)
- Higher blood pressure or fast heartbeat during infusion
- Lower oxygen levels during infusion
- Rash
- Headache
- Upper respiratory tract infection
- Injection site reaction
- Tingling or numbness (paresthesia)
- Tingling or numbness, and exaggerated reflexes
- Poor venous access (difficulty getting an IV in)
When to get medical help
- Get emergency help for signs of a severe allergic reaction, such as trouble breathing, wheezing, noisy breathing, swelling of the face or throat, hives, or a very slow heartbeat or low blood pressure. These can happen during the infusion or up to 3 hours afterward.
- Tell your care team right away if you have breathing trouble, worsening cough or chest symptoms during or after an infusion.
- Report signs of heart or lung strain, especially if you are prone to fluid overload.
- Tell staff right away about any severe reaction during an infusion, such as chills, fever, or blood pressure changes.
- Report pain, swelling or leaking at the IV site.
Anaphylaxis, severe breathing problems, and heart or lung failure are serious and need urgent attention.
Laronidase warnings and precautions
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- Severe allergic reactions (anaphylaxis) can occur during or up to 3 hours after infusion. Some have been life-threatening.
- Breathing problems: People with fever, respiratory illness, sleep apnea or upper airway blockage are at higher risk.
- Heart and lung failure: People prone to fluid overload may need a smaller infusion volume and slower rate.
- Infusion reactions can still occur despite premedication.
- Antibodies to the drug develop in most patients, and some are linked to anaphylaxis.
Before taking Laronidase
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- There are no listed contraindications.
- Tell your doctor about fever, respiratory illness, sleep apnea, or heart or lung problems.
- Tell your doctor if you have had a severe reaction to this drug.
- Pregnancy: data from over 30 pregnancies showed no drug-linked risk. Untreated MPS I can cause pregnancy problems, so decide with your doctor.
- Breastfeeding: data are limited. Discuss with your doctor.
- Children: studied from 6 months of age.
- Older adults: not studied in people 65 and older.
What Laronidase does in the body
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The effect of Aldurazyme was measured by a drop in urinary GAG levels. How urinary GAG changes with dose, and how it relates to other measures of clinical response, is not known.
How your body processes Laronidase
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After IV infusion, laronidase is cleared from the blood fairly quickly, with a half-life of about 1.5 to 3.6 hours in patients 6 and older. Younger children showed a similar short half-life. Most patients develop antibodies that can temporarily speed clearance of the drug.
How to store Laronidase
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Refrigerate vials of ALDURAZYME at 2°C to 8°C (36°F to 46°F). Do not freeze or shake. Protect from light.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Laronidase: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Laronidase — the kind of thing our pharmacy team would talk through with you at the counter.
What is Laronidase for?
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How is it given and how long does it take?
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What side effects should I expect?
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When should I worry about a reaction?
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Should I tell you if I'm sick before an infusion?
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Can I use it during pregnancy?
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Is Laronidase available over the counter?
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When was Laronidase first available?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Laronidase on HelloPharmacist
Laronidase forms and strengths (how it comes)
Laronidase is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Laronidase inactive ingredients by manufacturer.
Injection
How this form is used
- Aldurazyme treats Hurler and Hurler-Scheie forms of MPS I in adults and children.
- Aldurazyme treats the Scheie form of MPS I in patients with moderate to severe symptoms.
- Aldurazyme is given once weekly as an IV infusion after dilution in saline.
- Aldurazyme infusions take about 3 to 4 hours, with the rate increased in steps as tolerated.
- Aldurazyme should not be run through the same IV line as other products.
- Aldurazyme may be preceded by an antihistamine about 60 minutes before the infusion.
Laronidase on the U.S. market: products, makers and brands
How Laronidase appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
1 company lists 1 Laronidase product record with the FDA, mostly as injection; the earliest marketing or approval year on record is 2003. Brand names on the directory include Aldurazyme; the rest are generics.
How widely Laronidase is used (Medicaid data)
A general measure of how commonly Laronidase is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Laronidase is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Laronidase prescribed? Of the 1,601 medications we measure, Laronidase ranks #1,364 by Medicaid prescriptions — more than 15% of them.
Utilization by Laronidase product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
5 ML laronidase 0.58 MG/ML Injection
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 403822
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Laronidase, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 1 of 1 listed Laronidase NDCs with Medicaid activity.
Compare Laronidase products
A representative set of FDA-listed product records for Laronidase — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 2.9 mg/5 mL | Intravenous | Genzyme Corporation | BLA | View NDC → |
Showing 1 of 1 products — FDA National Drug Code Directory. See every product, package size and price: browse all 1 Laronidase NDCs →
Laronidase side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Laronidase — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Laronidase in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Laronidase FDA approval history
How Laronidase went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Laronidase recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Laronidase recalls since July 2021.
✅No Laronidase recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 392509 1 dose form · 1 strength
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Dose form (SCDF) Injection RxCUI 1860090In current FDA listingsClinical drug / strength (SCD) 5 ML laronidase 0.58 MG/MLRxCUI 403822
Look up RxCUI 392509 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Laronidase supply and shortage status
Whether Laronidase is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Laronidase brand names
Laronidase is sold under one brand name in the FDA directory — Aldurazyme. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Laronidase: manufacturers and labelers
One company lists Laronidase products with the FDA. By number of product records, the largest are Genzyme Corporation. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Laronidase drug class (RxNorm)
Laronidase belongs to the Hydrolytic Lysosomal Glycosaminoglycan-specific Enzyme class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Laronidase page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Genzyme Corporation is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →