The Evaluation and Management of Methimazole-Induced Agranulocytosis in the Pediatric Patient: A Case Report and Review of the Literature

Abstract

Introduction: Agranulocytosis is a rare but serious complication of methimazole (MMI) use for Graves' disease (GD). Treatment requires discontinuation of MMI, and the use of propylthiouracil (PTU) is also contraindicated. Few reports exist about the optimal alternative treatment regimens for the management of thyrotoxicosis in these medically complex patients in the pediatric population.

Case report: We report prolonged saturated solution of potassium iodide (SSKI) use (29 days) in a 17-year-old female with GD and MMI-induced agranulocytosis, who presented with septic shock. Her treatment course also included β-blockade, cholestyramine, and granulocyte colony stimulating factor. We performed a review of the literature on the use of SSKI in the management of thyrotoxicosis, as well as best practices from the view of endocrinology, infectious disease, hematology, surgery, and intensivists, for the evaluation and management of MMI-induced agranulocytosis.

Discussion: The management of MMI-induced agranulocytosis and associated sequelae require subspecialty input and intensive evaluation and monitoring. Alternative treatments to manage hyperthyroidism and control symptoms of thyrotoxicosis during agranulocytosis are a bridge to definitive therapy and include β-blockade, SSKI, cholestyramine, steroids, lithium, and plasmapheresis.

Introduction: Agranulocytosis is a rare but serious complication of methimazole (MMI) use for Graves' disease (GD). Treatment requires discontinuation of MMI, and the use of propylthiouracil (PTU) is also contraindicated. Few reports exist about the optimal alternative treatment regimens for the management of thyrotoxicosis in these medically complex patients in the pediatric population.

Case report: We report prolonged saturated solution of potassium iodide (SSKI) use (29 days) in a 17-year-old female with GD and MMI-induced agranulocytosis, who presented with septic shock. Her treatment course also included β-blockade, cholestyramine, and granulocyte colony stimulating factor. We performed a review of the literature on the use of SSKI in the management of thyrotoxicosis, as well as best practices from the view of endocrinology, infectious disease, hematology, surgery, and intensivists, for the evaluation and management of MMI-induced agranulocytosis.

Discussion: The management of MMI-induced agranulocytosis and associated sequelae require subspecialty input and intensive evaluation and monitoring. Alternative treatments to manage hyperthyroidism and control symptoms of thyrotoxicosis during agranulocytosis are a bridge to definitive therapy and include β-blockade, SSKI, cholestyramine, steroids, lithium, and plasmapheresis.

Keywords: Adverse reactions; Agranulocytosis; Graves’ disease; Methimazole; Pediatrics.