methimazole and Pruritus

A 39-year-old multigravida woman presented 3 weeks postpartum with worsening generalised pruritus without primary rash. Workup was significant for cholestasis and undiagnosed Graves' disease. She began to have symptomatic relief after starting methimazole, and liver function tests normalised as she became euthyroid.

Topics: Antithyroid Agents; Female; Graves Disease; Humans; Liver Function Tests; Methimazole; Postpartum Period; Pruritus; Treatment Outcome; Young Adult

A 12-year-old neutered male domestic shorthair cat presented for chronic, localized, swelling and crusting of the left upper lip, weight loss, sporadic vomiting, and focal alopecia between the scapulae was diagnosed with hyperthyroidism and regional eosinophilic lymphadenitis. Treatment with methimazole exacerbated an underlying hypersensitivity disorder leading to marked generalized lymphadenopathy that histologically mimicked lymphoma.

Topics: Animals; Cat Diseases; Cats; Hyperthyroidism; Lymphatic Diseases; Male; Methimazole; Pruritus

Methimazole is a widely used and generally well-tolerated antithyroid agent. A 43-year-old woman had severe jaundice and itching 1 month after receiving methimazole (10 mg tid) and propranolol (20 mg tid) for treatment of hyperthyroidism. The patient continued treatment for another 4 days after the appearance of jaundice until she finished both medications. When seen at the emergency department 2 weeks later, she still had severe icterus, pruritus, and hyperbilirubinemia, formed mainly of the conjugated fraction. Methimazole-induced cholestasis was diagnosed, and propranolol therapy was resumed. Over the following 9 days, the symptoms improved and plasma bilirubin levels were normal after 12 weeks without methimazole. In rare cases within the first few weeks of therapy, this drug can cause severe and reversible cholestatic jaundice. Physicians and patients should be aware of this adverse effect so that, upon occurrence, they can discontinue methimazole therapy and avoid unnecessary invasive procedures.

Topics: Adult; Aged; Antithyroid Agents; Female; Humans; Jaundice, Obstructive; Male; Methimazole; Middle Aged; Pruritus

Topics: Agranulocytosis; Antithyroid Agents; Drug Eruptions; Humans; Hyperthyroidism; Imidazoles; Male; Methimazole; Pruritus; Urticaria

Topics: Adult; Aged; Catecholamines; Child; Female; Humans; Hyperthyroidism; Iodine Isotopes; Methimazole; Middle Aged; Pruritus; Thyroid Function Tests; Urticaria