IV iron formulations linked to varying risks for anaphylaxis in older adults: Study
New Jersey: The rates of anaphylaxis after administration of all IV iron products are very low but are 3- to 8-fold higher for iron dextran and ferumoxytol than for iron sucrose, a recent study has found. The study was published in the Annals of Internal Medicine on 29 March 2022.
The study was conducted by Chintan V. Dave and the team from New Jersey conducted the study with an aim to compare risks for anaphylaxis among 5 IV iron products that are used frequently in a retrospective cohort study using a target trial emulation framework.
The study was done with Medicare fee-for-service data with Part D coverage between July 2013 and December 2018 and included older adults receiving their first administration of IV iron.
The occurrence of anaphylaxis within 1 day of IV iron administration, ascertained using a validated case definition was the primary outcome. Using the inverse probability of treatment weighting, analysis was adjusted for 40 baseline covariates. The researchers computed the adjusted incidence rates (IRs) for anaphylaxis per 10 000 first administrations and odds ratios.
Salient findings of the study include:
- The adjusted IRs for anaphylaxis per 10 000 first administrations were 9.8 cases for iron dextran, 4.0 cases for ferumoxytol, 1.5 cases for ferric gluconate, 1.2 cases for iron sucrose, and 0.8 cases for ferric carboxymaltose.
- Using iron sucrose as the referent category, the adjusted ORs for anaphylaxis were 8.3 for iron dextran and 3.4 for ferumoxytol.
- When cohort entry was restricted to the period after withdrawal of high-molecular-weight iron dextran from the U.S. market in 2014, the risk for anaphylaxis associated with low-molecular-weight iron dextran (OR, 8.4) did not change appreciably.
- Anaphylactic reactions requiring hospitalizations were observed only among patients using iron dextran or ferumoxytol.
"While the risk of anaphylaxis following administration of IV iron product was low among older adults," the authors concluded.
Reference:
The study titled, "Risks for Anaphylaxis With Intravenous Iron Formulations," was published in the Annals of Internal Medicine.
DOI: https://doi.org/10.7326/M21-4009
KEYWORDS: Annals of Internal Medicine, IV iron, iron products, anaphylaxis, iron dextran, ferumoxytol, iron sucrose, ferric gluconate, ferric carboxymaltose, Chintan V Dave
