Related Experiment Video

Updated: May 19, 2026

Human Liver Microphysiological System for Assessing Drug-Induced Liver Toxicity In Vitro
11:06

Human Liver Microphysiological System for Assessing Drug-Induced Liver Toxicity In Vitro

Published on: January 31, 2022

Sudden onset agranulocytosis and hepatotoxicity after taking methimazole

Jing Yang1, Jing Zhong, Ling-Zhi Zhou

  • 1Department of Metabolism & Endocrinology of the First Affiliated Hospital, University of South China, China.

Internal Medicine (Tokyo, Japan)
|August 16, 2012
PubMed

Insights

Methimazole can cause agranulocytosis, a dangerous drop in white blood cells, and liver damage. This rare side effect can occur suddenly, even within days of starting treatment for Graves' disease.

Area of Science:

  • Endocrinology
  • Pharmacology
  • Hepatology

Background:

  • Methimazole is a common treatment for Graves' disease.
  • Agranulocytosis is a known, though rare, adverse effect of methimazole.
  • Hepatotoxicity is also a rare side effect associated with methimazole.

Observation:

  • This report details an unusual case of a Graves' disease patient experiencing rapid-onset agranulocytosis and hepatotoxicity.
  • Symptoms developed within six days of initiating methimazole therapy, which is significantly faster than typical presentations.
  • This case highlights an extreme idiosyncratic reaction to methimazole.

Findings:

  • The patient exhibited severe agranulocytosis and concurrent hepatotoxicity shortly after methimazole administration.
  • The rapid onset contrasts with the generally accepted timeline of 1-4 months for methimazole-induced agranulocytosis.
  • This suggests a potential for very acute idiosyncratic reactions.

Implications:

  • Increased physician awareness of sudden-onset methimazole-induced agranulocytosis and hepatotoxicity is crucial.
  • Prompt recognition and management are vital for patient outcomes.
  • Further investigation into the mechanisms of idiosyncratic drug reactions may be warranted.

Related Concept Videos

Drug toxicity: Idiosyncratic Reactions01:16

Drug toxicity: Idiosyncratic Reactions

Idiosyncratic drug reactions represent abnormal chemical responses that vary significantly among individuals, ranging from extreme sensitivity to low doses to insensitivity to high doses. These reactions often occur due to the drug's covalent binding with serum proteins, forming a foreign hapten that triggers an immunotoxicological response. The variability in drug reactions has a strong pharmacogenetic foundation, with genetic differences crucial in how individuals metabolize drugs. For...
Graves' Disease I: Introduction01:28

Graves' Disease I: Introduction

Graves' disease is an autoimmune disorder that causes hyperthyroidism, or overactivity of the thyroid gland. It results from autoantibodies called thyroid-stimulating immunoglobulins (TSIs), which bind to thyroid-stimulating hormone (TSH) receptors, leading to overstimulation of hormone production and a hypermetabolic state.EtiologyAlthough considered idiopathic, Graves’ disease has well-established contributing factors. There is a strong genetic component, with increased prevalence in...
Drug Toxicity: Allergic Reactions01:30

Drug Toxicity: Allergic Reactions

Drug-related allergies are immune-mediated responses triggered by the administration of pharmacological agents. These hypersensitivity reactions are classified based on the immune mechanisms involved. The four primary types—Type I, II, III, and IV—are mediated by different immunological pathways and exhibit distinct clinical manifestations.Type I Hypersensitivity/ IgE-Mediated Reactions: Immunoglobulin E (IgE) immediately mediates Type I hypersensitivity reactions. Upon initial exposure to a...
Graves Disease II: Pathophysiology01:24

Graves Disease II: Pathophysiology

Graves’ disease is an autoimmune disorder characterized by the production of thyroid-stimulating immunoglobulins (TSI) that activate TSH receptors, leading to excessive synthesis and release of thyroid hormones (T3 and T4) and resulting in hyperthyroidism.Among all causes of hyperthyroidism, Graves’ disease is the most common and can happen at any age, though it is more frequent in women. It produces a hypermetabolic state with features such as weight loss, tachycardia, tremor, and heat...
Drug toxicity: Drug–Drug Interaction01:30

Drug toxicity: Drug–Drug Interaction

Drug–drug interactions can precipitate toxicity through multiple mechanisms. Absorption interactions alter how drugs enter the body, exemplified when ranitidine increases the absorption of basic drugs, while cholestyramine decreases the levels of propranolol. Protein binding interactions occur when drugs share the same binding sites on plasma proteins. Drugs like aspirin and warfarin, when bound in excess, can lead to increased free drug concentrations, enhancing the potential for...
Hypersensitivity Reactions: Cytolytic Reactions01:01

Hypersensitivity Reactions: Cytolytic Reactions

Type II hypersensitivity involves IgG and IgM antibodies targeting cell surface antigens, leading to cell destruction. This can occur through complement activation, antibody-dependent cell-mediated cytotoxicity (ADCC), or acting as opsonins for phagocytosis. When excessive, these reactions cause significant tissue damage.Drug-induced hemolytic anemia is a common example, where drugs like penicillin or cephalosporins bind to red blood cells, forming drug-protein complexes. These complexes...