ARTICLE TYPE : REVIEW ARTICLE
Published on : 10 Oct 2026,
Volume - 2
Journal Title :
WebLog Journal of Thyroid Research
| WebLog J Thyroid Res
| WJTR
Source URL:
https://weblogoa.com/articles/wjtr.2026.j1002
Permanent Identifier (DOI) :
State of Art Antithyroid Drug-Induced Neutropenia and Agranulocytosis
2Referral Centre of Immune Cytopenias, University Hospital of Strasbourg, 67084 Strasbourg, France
3Institute of Physiology, FMTS-EA 3072, Faculty of Medicine, University of Strasbourg, 67000 Strasbourg, France
4Department of Internal Medicine, University Hospital of Oujda, 59000 Oujda, Morocco
Abstract
Antithyroid Drugs (ATDs) - principally carbimazole, methimazole (thiamazole), and propylthiouracil - remain central to the treatment of hyperthyroidism but can rarely cause idiosyncratic neutropenia and agranulocytosis, a potentially fatal adverse drug reaction. Agranulocytosis is conventionally defined by an absolute neutrophil count below 0.5×109/L and may develop abruptly after a previously normal blood count. This Seminar reviews contemporary epidemiology, drug- and patient-related risk factors, mechanisms, pharmacogenomic susceptibility, clinical presentation, differential diagnosis, monitoring, and management. Risk is heterogeneous and reflects ATD exposure, dose, age, population, and genetic background. HLA-B*38:02 and HLA-DRB1*08:03 are strongly associated with susceptibility in several Asian populations, whereas HLA-B*27:05 is particularly relevant in European cohorts; these associations are not yet sufficient to support universal pre-treatment screening. Fever, sore throat, or other infectious symptoms during ATD treatment should prompt immediate blood-cell assessment, and confirmed or strongly suspected agranulocytosis requires immediate withdrawal of the culprit drug. Febrile profound neutropenia is a medical emergency requiring prompt empirical antimicrobial therapy. G-CSF can accelerate neutrophil recovery in selected patients, although an independent mortality benefit remains unproven. After true ATD-induced agranulocytosis, re-exposure should be avoided and definitive treatment with radioiodine or thyroidectomy should be considered. Prevention therefore rests primarily on patient education and rapid symptom-triggered testing, with selective periodic monitoring where local circumstances justify it. Prospective validation of population-specific pharmacogenomic and clinical risk models is now needed to determine whether earlier detection or genotype-guided treatment improves patient-important outcomes.
Keywords: Antithyroid Drugs; Carbimazole; Methimazole; Propylthiouracil; Neutropenia; Agranulocytosis; Graves' Disease; Pharmacogenomics; G-CSF; Pharmacovigilance
Citation
Andrès E, Jannot X, Terrade J-E, Serraj K, Lorenzo-Villalba N. State of Art Antithyroid Drug-Induced Neutropenia and Agranulocytosis. WebLog J Thyroid Res. wjtr.2026.j1002. https://doi.org/10.5281/zenodo.23336387