Idursulfase

How it works

It provides the deficient enzyme iduronate-2-sulfatase, enabling catabolism of dermatan and heparan sulfate and reducing glycosaminoglycan accumulation.

Prescribing in practice

• Serious infusion-related and anaphylactoid reactions can occur, so give under supervision with resuscitation facilities and monitor closely during and after infusion.
• It should be initiated and supervised by a clinician experienced in lysosomal storage disorders.
• It does not cross the blood-brain barrier and so does not treat central nervous system manifestations of the disease.

Monitoring

Monitor for hypersensitivity reactions with each infusion and review clinical response, including respiratory and functional measures, over time.

Counselling the patient

• Infusions are given regularly with monitoring for reactions such as rash, fever or breathing difficulty.
• Tell staff at once if you or your child feel unwell during an infusion.
• This treatment helps systemic symptoms but does not reverse intellectual or neurological effects.

Evidence & guidelines

Enzyme replacement for Hunter syndrome is an established orphan therapy supported by randomised controlled trial data.