Galsulfase

INTRODUCTION

Indications

Mucopolysaccharidosis VI (MPS IV).

Action

Replaces a deficient enzyme in MPS IV. Without replacement, glycosaminoglycans accumulate resulting in cell, organ, and tissue dysfunction. Therapeutic Effects: Improved walking and stair climbing.

Adverse Reactions/Side Effects

CV: malaise. EENT: conjunctivitis, corneal opacification, ear pain. Resp: dyspnea. CV: chest pain, ↑ blood pressure. Derm: facial edema. GI: gastroenteritis, abdominal pain. MS: areflexia. Misc: INFUSION REACTIONS, rigors.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Be alert for allergy-like responses (wheezing, laryngeal edema, urticaria, other skin reactions) that occur during and after administration (infusion reactions). Report these responses to the physician or nursing staff immediately.

• Assess ambulation on level surfaces and during stair climbing. Document any changes in functional ability to help document whether drug therapy is effective in maintaining or improving motor function.

• Monitor any changes in muscle tone or deep tendon reflexes. Report increased muscle contractions or decreased reflex activity.

• Assess blood pressure (BP) and compare to normal values (See Appendix F). Report a sustained increase in BP (hypertension) or any chest pain or difficult, labored breathing.

• Monitor and report any vision problems, eye inflammation, or ear pain.

Interventions

• Implement therapeutic exercises (resistive training, coordination exercises, gait training) to complement the effects of drug therapy and help achieve optimal function.

Patient/Client-Related Instruction

• Instruct patient and family/caregivers to report other troublesome side effects such as severe or prolonged malaise, facial swelling, or GI problems (gastroenteritis, abdominal pain).

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Widely distributed.

Metabolism and Excretion: Unknown.

Half-life: 9 min (after 1 wk of treatment, 26 min (after 24 wk of treatment).

Contraindications/Precautions

Contraindicated in: None.

Use Cautiously in: Febrile or respiratory illness; Pedi: Children <5 yr (safety not established); OB: Pregnancy or lactation (safety being evaluated).

Interactions

Drug-Drug: None noted.

Route/Dosage

IV (Adults and Children >5 yr): 1 mg/kg once weekly.

Availability

Solution for IV administration (diluted prior to use): 5 mg/5 mL in 5-mL vials.