idursulfase

(i-dur-sul-fase) idursulfase,

Elaprase

(trade name)

Classification

Therapeutic: replacement enzyme
Pharmacologic: enzymes
Pregnancy Category: C

Indications

Treatment of Mucopolysaccharidosis II (MPS II, Hunter syndrome).

Action

Replaces an enzyme not present in Hunter syndrome. Absence of the enzyme results in cellular accumulation of aminoglycans, organomegaly and organ dysfunction.

Therapeutic effects

Improved walking capacity.

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.Distribution: Unknown.Metabolism and Excretion: unknownnown.Half-life: 44–48 min.

Time/action profile

ROUTE	ONSET	PEAK	DURATION
IV	rapid	end of infusion	unknown

Contraindications/Precautions

Contraindicated in: No known contraindications.Use Cautiously in: Compromised respiratory function/acute respiratory disease (increased risk of infusion reactions); Severe genetic mutations (↑ risk of serious adverse reactions)Patients at risk for fluid overload, acute respiratory disorder, cardiac or respiratory illness (↑ risk of compromised cardiac or respiratory function) Obstetric: Use in pregnancy only if clearly needed; Obstetric: Use cautiously in lactation; Pediatric: Children <16 mo (safety not established).

Adverse Reactions/Side Effects

Central nervous system

headache (most frequent)
malaise

Cardiovascular

hypertension

Gastrointestinal

dyspepsia

Dermatologic

cutaneous reactions (most frequent)

Local

infusion site swelling

Musculoskeletal

arthralgia (most frequent)

Miscellaneous

anaphylaxis (life-threatening)
fever (most frequent)

Interactions

Drug-Drug interaction

None noted.

Route/Dosage

Intravenous (Adults and Children ≥5 yr) 0.5 mg/kg weekly

Availability

Solution for IV infusion (requires dilution): 2 mg/mL

Nursing implications

Nursing assessment

Observe for signs and symptoms of anaphylaxis (rash, pruritus, laryngeal edema, wheezing) during and for 24 hrs after infusion. Keep epinephrine, an antihistamine, corticosteroids, and resuscitation equipment close by in case of anaphylactic reaction.
Monitor for infusion-related reactions (headache, fever, rash, pruritus, erythema, urticaria, hypertension. Most reactions are managed with antihistamines and/or corticosteroids prior to or during infusions, slowing rate of infusion, and/or early discontinuation if reaction is serious.

Potential Nursing Diagnoses

Impaired physical mobility (Indications)

Implementation

Patients with compromised respiratory function or acute respiratory disease are at increased risk of life-threatening infusion reactions. Consider delaying infusion in patients with concomitant acute respiratory and/or febrile illness.
Intermittent Infusion: Determine number of vials required for the dose ordered. If number of vials includes a fraction, round up to next whole number. Vials are for single use; discard remaining medication. Dilute each vial in 100 mL of 0.9% NaCl. Use an infusion set with a 0.2 micrometer filter for administration. Mix gently; do not shake solution. Solution is clear to slightly opalescent; do not administer solutions that are discolored or contain particulate matter. Solution may be stored in refrigerator for up to 48 hr. Discard solution of not administered or refrigerated within 8 hrs.
Rate: Administer at 8 mL/hr for first 15 min. If well tolerated, may increase by 8 mL/hr at 15 min intervals to administer total volume within desired time. Do not exceed 100 mL/hr. May slow, temporarily stop, or discontinue for that visit if infusion reactions occur. Administer total infusion over 1–3 hrs. May require longer times if infusion reactions occur; should not exceed 8 hrs.
Y-Site Incompatibility: Do not administer other medications or solutions in same tubing as idursulfase.

Patient/Family Teaching

Explain purpose of infusion to patient and parents.
Advise female patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
Inform patient that a Hunter Outcome Survey was established to evaluate long term treatments. For information, visit www.elaprase.com or call 1–866–888–0660.

Evaluation/Desired Outcomes

Improved walking capacity in patients with Hunter syndrome.