Idursulfase: adverse event reports filed with FDA

2,170

reports as suspect product

0% of all reports · about 114 a year

133

reports, 12 months to June 2026

119 in the 12 months before

96.2%

marked serious by the reporter

63.8% across the class

17.2%

record death among outcomes, as reported

373 reports · not verified by FDA

Reports by month, five years

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Idursulfase reports recording the termmedian drug in hydrolytic lysosomal glycosaminoglycan-specific enzyme

1. Product dose omission issuea dose was missed21.8%473
2. Pyrexiafever20.2%438
3. Inappropriate schedule of product administrationthe product was taken at the wrong times16.2%351
4. Coughcough10.9%236
5. Pneumonialung infection9.4%203
6. Product availability issuethe product was not available8.9%194
7. Influenzaflu8.6%186
8. Covid-19COVID-19 infection8.2%179
9. Weight increasedweight gain7.9%171
10. Seizurea fit or convulsion7.7%167
11. Dyspnoeashortness of breath7.6%166
12. Poor venous access7.4%161
13. Deaththe patient died; cause not stated by this term7%151
14. Illness6.7%146
15. Malaisegeneral feeling of being unwell6.7%146
16. Nasopharyngitisa cold6.5%141
17. Incorrect dose administeredthe wrong dose was given6.4%139
18. Infusion related reactiona reaction during or soon after an infusion6.2%134
19. Diarrhoealoose or frequent stools6%130
20. Vomitingbeing sick5.6%122
21. Weight decreasedweight loss5.4%117
22. Rhinorrhoeaa runny nose5.2%113
23. Productive cougha cough with phlegm4.7%101
24. Painpain, site not specified4.4%96
25. Treatment noncompliancethe treatment was not taken as directed4.4%96
26. Falla fall3.8%83
27. Fatiguetiredness3.7%81
28. Product use issuea problem in how the product was used3.7%81
29. Ear infectionan ear infection3.6%78
30. Headachehead pain3.5%77

Top 30 of 702 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 6 drugs in the hydrolytic lysosomal glycosaminoglycan-specific enzyme class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 17,202 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 30% of reports give the United States as the country of the event or reporter.

Reason for use recorded

The indication field is filled in by the reporter and is often blank; shares are of all 2,170 reports.

Drugs most often listed in the same reports

Other products listed in reports where Idursulfase is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Other drugs in the hydrolytic lysosomal glycosaminoglycan-specific enzyme class

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Idursulfase as a suspect or interacting product; reports listing it only as a concomitant medication (14) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.