alglucosidase

alglucosidase

(al-gloo-ko-side-ase) ,

Lumizyme

(trade name),

Myozyme

(trade name)

Classification

Therapeutic: replacement enzyme

Pregnancy Category: B

Indications

Myozyme: Replacement enzyme in infantile-onset Pompe disease (alpha glucosidase (GAA) deficiency).Lumizyme: Replacement enzyme in late-onset (non-infantile) Pompe disease in patients without evidence of cardiac hypertrophy.

Action

Replaces alpha-glucosidase. Without this enzyme, glycogen accumulates in tissues including cardiac and skeletal muscles and hepatic tissues, leading to the development of cardiomyopathy, progressive muscle weakness, and impairment of respiratory function.

Therapeutic effects

Improved survival with delayed need for ventilatory support.

Improved lung function and exercise capacity.

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Metabolism and Excretion: Unknown.

Half-life: 2.3–2.5 hr.

Time/action profile

ROUTE	ONSET	PEAK	DURATION
IV	unknown	end of infusion	2 wk

Contraindications/Precautions

Contraindicated in: None known.

Use Cautiously in: Acute underlying illness (↑ risk of infusion reactions); Obstetric: Use only if clearly needed; Lactation: Lactation; Pediatric: Safety not established in children <1 mo or >3.5 yr (Myozyme) or <8 yr (Lumizyme).

Adverse Reactions/Side Effects

Cardiovascular

• bradycardia (most frequent)
• tachycardia (most frequent)

Respiratory

• respiratory distress failure
• cough (most frequent)
• ↓ oxygen saturation (most frequent)
• tachypnea

Ear, Eye, Nose, Throat

• blurred vision
• vertigo

Gastrointestinal

• constipation (most frequent)
• diarrhea (most frequent)
• reflux (most frequent)
• vomiting (most frequent)

Dermatologic

• necrotizing skin lesions (life-threatening)
• flushing (most frequent)
• rash (most frequent)
• dermatitis (most frequent)
• urticaria (most frequent)

Hematologic

• anemia (most frequent)
• lymphadenopathy

Fluid and Electrolyte

• edema

Miscellaneous

• allergic reactions including anaphylaxis (life-threatening)
• infusion reactions (life-threatening)
• fever (most frequent)

Interactions

Drug-Drug interaction

None noted.

Route/Dosage

Intravenous (Children 1 mo–3.5 yr) Myozyme—20 mg/kg every 2 wk.

Intravenous (Adults and Children ≥8 yr) Lumizyme—20 mg/kg every 2 wk.

Availability

Lyophilized powder for IV administration (requires reconstitution): 50 mg/vial

Nursing implications

Nursing assessment

• Observe for signs and symptoms of anaphylaxis (rash, pruritus, laryngeal edema, wheezing). Keep epinephrine, an antihistamine, corticosteroids, and resuscitation equipment close by in case of anaphylactic reaction.
• Monitor for infusion-related reactions (headache, fever, tachycardia, cough, cyanosis, rash, erythema, urticaria, hypotension. 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. Infusion reactions may occur any time during or up to 2 hr after infusion and are more likely with higher infusion rates.
• Monitor cardiorespiratory status continuously during therapy. May cause acute cardiorespiratory failure requiring intubation and inotropic support.
• Lab Test Considerations: Monitor liver enzymes prior to and periodically during therapy.

Potential Nursing Diagnoses

Ineffective tissue perfusion (Indications)

Implementation

• Lumizyme is available only through a restricted distribution program called the LUMIZYME ACE Program due to the potential risk of rapid disease progression in Pompe disease patients less than 8 yrs of age. Only prescribers and healthcare facilities enrolled in the program may prescribe, dispense or administer Lumizyme. Lumizyme may be administered only to patients who are enrolled in and meet all the conditions of the Lumizyme ACE Program. To enroll in the Lumizyme ACE Program call 1-800-745-4447.

• Intravenous Administration

• Intermittent Infusion: Determine number of vials required for the dose ordered. If number of vials includes a fraction, round up to next whole number. Allow vials to reach room temperature before reconstitution, approximately 30 min. Reconstitute by slowly injecting 10.3 mL of Sterile Water for Injection to inside wall of each vial. Avoid forceful impact of water on powder to avoid foaming. Tilt and roll each vial gently. Do not invert, swirl, or shake. Protect solution from light. Each vial contains 5 mg/mL with a total extractable dose of 50 mg/10 mL. Solution is clear and may occasionally contain white strands or translucent fibers; do not administer solutions that are discolored or contain particulate matter. Vials are for single use; discard remaining medication. Diluent: Dilute each vial in 100 mL of 0.9% NaCl immediately after reconstitution. Concentration: 0.5–4 mg/mL. Slowly withdraw reconstituted solution from each vial. Remove airspace from infusion bag to minimize particle formation due to sensitivity of medication to air. Add reconstituted solution slowly and directly into 0.9% NaCl solution, not into airspace in bag. Gently invert or massage to mix; do not shake. Use a 0.2 micrometer low-protein binding in-line filter for administration. Administer immediately. Solution may be stored in refrigerator for up to 24hr.
• Rate: Administer over 4 hr. Using an infusion pump, administer initially at a rate of 1 mg/kg/hr. ↑ rate to 2 mg/kg/hr every 30 min, after tolerance to medication is established, until a maximum rate of 7 mg/kg/hr is reached. Monitor vital signs with each dose ↑. If stable, administer at 7 mg/kg/hr until infusion is completed. Slow or temporarily stop infusion if infusion reactions occur.

Patient/Family Teaching

• Inform patient that a registry for patients with Pompe disease was established to evaluate long term treatments. Women of childbearing potential are also encouraged to register. For information, visit www.pomperegistry.com or call 1-800-745-4447.

Evaluation/Desired Outcomes

• Improved survival with delayed need for ventilatory support in patients with Pompe disease.
• Improved lung function and exercise capacity.