Pregnancy Category: B
ClassificationTherapeutic: replacement enzyme
Mucopolysaccharidosis 1 (MPS 1; specifically Hurler and Hurler-Scheie form or Scheie form) with moderate to severe symptoms.
Replaces the naturally occurring enzyme α-L-iduronidase which is deficient in MPS 1. Without replacement, the glucosaminoglycans dermatan and heparan accumulate in tissues.
Decreased cellular, tissue and organ damage due to mucopolysaccharide accumulation resulting in improved pulmonary function and walking capacity.
Absorption: IV administration results in complete bioavailability.
Metabolism and Excretion: Unknown.
Half-life: 1.5–3.6 hr.
Contraindicated in: None known.
Use Cautiously in: Obstetric: Use during pregnancy only if clearly needed; Lactation: Safety not established.
Adverse Reactions/Side Effects
Central nervous system
- respiratory tract infections
- injection site reactions
- allergic reactions including anaphylaxis (life-threatening)
- infusion related reactions
Drug-Drug interactionNone known.
Intravenous (Adults and Children) 0.58 mg/kg once weekly, pre-treat with antipyretics and/or antihistamines.
Solution for injection: 0.58 mg/mL
- Assess vital signs every 15 min during the first hr of the infusion and frequently during remainder of infusion.
- Monitor for signs of anaphylaxis (dyspnea, rash, urticaria) during and for up to 3 hrs following infusion. May be treated by slowing infusion rate, additional antipyretics and antihistamines. If severe reaction occurs, discontinue infusion and institute treatment. Use caution when considering epinephrine; these patients have an increased prevalence of coronary artery disease.
- Monitor for infusion-related reaction (flushing, fever, headache, rash). Treat by slowing infusion rate, temporarily stopping infusion, and/or administering antipyretics and antihistamines.
Potential Nursing DiagnosesImpaired gas exchange (Indications)
- Administer antipyretics and antihistamines 60 min prior to infusion to prevent hypersensitivity reactions.
- Intermittent Infusion: Diluent: Dilute concentrated solution with 0.1% albumin and 0.9% NaCl using PVC containers. Determine number of vials needed based on patient weight and round to nearest whole vial. Remove required number of vials from refrigerator and allow to reach room temperature; do not heat or microwave vials. Solution in vials should be slightly opalescent and colorless to pale yellow and may contain a few translucent particles; do not use if discolored or contain particulate matter. Refrigerate, do not freeze. Laronidase administration must be completed within 36 hr of preparation. Do not use after expiration date.
- Determine total volume of infusion based on weight. Final volume should be 100 mL if patient weighs ≤20 kg and 250 mL if patient weighs >20 kg.
- To prepare infusion, remove and discard amount of 0.9% NaCl from infusion bag equal to amount of albumin to be added. If total volume is 100 mL, add 2 mL of albumin 5% or 0.4 mL of albumin 25%; if total volume is 250 mL, add 5 mL of albumin 5% or 1 mL of albumin 25%. Gently rotate infusion bag to ensure distribution of albumin.
- Withdraw and discard a volume of 0.1% albumin in 0.9% NaCl equal to the volume of laronidase concentrate to be added. Slowly withdraw volume of laronidase from vial; avoid excessive agitation. Do not use a filter needle; may cause agitation and denature laronidase rendering it biologically inactive. Slowly add laronidase to 0.1% albumin in 0.9% NaCl solution. Gently rotate infusion bag to ensure distribution; do not shake.
- Rate: Administer with a low-protein-binding infusion set equipped with an in-line, low-protein-binding 0.2 micrometer filter over 3–4 hr. Initial infusion rate of 10 mcg/kg/hr can be increased every 15 min during first hr, as tolerated, until a maximum rate of 200 mcg/kg/hr is reached; then maintain maximum infusion rate for remainder of infusion (2–3 hr).
- Additive Incompatibility: Do not mix with other medications.
- Explain MPS I registry to patient and encourage participation. Purpose is to better understand the variability and progression of MPS I disease and to continue to monitor and evaluate treatments. Advise patients that participation may involve long-term follow-up. Information regarding the registry program can be found at www.MPSIregistry.com or by calling (800) 745-4447.
- Advise patient of risk of anaphylaxis. Caution patient to inform health care professional immediately if side effects occur.
- Advise female patients to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
- Improvement in pulmonary function and walking capacity. Full benefits may not be evident for several months to several years.