Summary

Thionamides, such as methimazole and propylthiouracil, are used for the management of hyperthyroidism. Agranulocytosis is a rare adverse effect of thionamides and elderly patients are especially vulnerable. Here we discuss a case of an 80-year-old woman who developed agranulocytosis and pneumonia approximately 4 weeks after starting low dose methimazole therapy. Despite aggressive treatment with broad-spectrum antibiotics and granulocyte colony stimulating factor, she developed multiorgan failure and died. Our goals are to identify risk factors common to elderly patients and hopefully improve outcomes in this population when prescribed thionamides.