Agranulocytosis secondary to propylthiouracil

Graves' Disease Thyrotoxicosis and Propylthiouracil Related Agranulocytosis Successfully Treated with Therapeutic Plasma Exchange and G-CSF Followed by Total Thyroidectomy

Antithyroid drugs can be a rare cause of agranulocytosis (0.5% of treated patients). Suspension of these drugs is mandatory in these patients and may result in worsening hyperthyroidism. We report the case of a 27-year-old woman who is 3 months post-partum, breastfeeding, and suffering with Graves’ disease hyperthyroidism treated first with methimazole and then with propylthiouracil due to a methimazole allergy. She was admitted for urosepsis and agranulocytosis. The patient was diagnosed with propylthiouracil related agranulocytosis, diffuse toxic goiter and thyro-gastric syndrome. Antithyroid drug therapy was stopped resulting in a worsening of thyrotoxicosis. Agranulocytosis was treated with 8 doses of G-CSF with full recovery. To rapidly restore euthyroidism and to perform a thyroidectomy, the patient received 6 therapeutic plasma exchange (TPE) procedures, to clear thyroid hormones and anti-TSH receptor antibodies from blood, resulting in a pre-surgical euthyroid state without antithyroid drug therapy. Two years after thyroidectomy, the patient is well under thyroid hormone replacement therapy with a normal granulocyte count.

Patient knowledge of antithyroid drug-induced agranulocytosis

BACKGROUND

Agranulocytosis is a serious side effect of antithyroid drugs.

OBJECTIVE

To ascertain the knowledge of patients and review the quality of information available on the internet.

METHODS

A questionnaire survey was performed for patients receiving antithyroid drugs. Patients attending endocrine clinics who were receiving antithyroid drug treatment (group A, n = 33) were interviewed. A further national cohort of patients (group B, n = 100) treated with antithyroid drugs, participated in an online survey.

RESULTS

60.9% of responders were not aware of the common symptoms of agranulocytosis. 18.6% had never received any information about side effects. Of the 108 patients who recalled receiving information, 30% rated the quality as 'poor' or 'not good at all'. Structured interviews of group A patients revealed that almost half (45.5%, 15/33) had experienced symptoms that could be indicative of agranulocytosis, but only 53.3% (8/15) had a blood count checked. A review of 20 selected patient information internet sites revealed a significant variation in advice given to patients.

CONCLUSIONS

Inadequate knowledge about agranulocytosis among patients receiving antithyroid drug treatment is common. The available information on the internet is variable and inconsistent.