Medication Card: Methimazole

What class of medication is Methimazole?

Antithyroid agent

How does Methimazole work in the body?

It inhibits the synthesis of thyroid hormones by interfering with the incorporation of iodine into tyrosine residues of thyroglobulin.

What are the primary indications for Methimazole?

Hyperthyroidism (especially Graves' disease), preoperative preparation for thyroidectomy, and thyrotoxic crisis.

Why is Methimazole contraindicated during pregnancy, especially in the first trimester?

it is associated with congenital malformations and adverse fetal outcomes. Propylthiouracil (PTU) is preferred during this time as it has a safer profile for the developing fetus, particularly in preventing the risk of teratogenic effects that Methimazole may induce.

What caution should be taken when prescribing Methimazole?

Use with caution in patients with hepatic impairment, bone marrow suppression, and those at risk for infection.

What serious adverse effect can Methimazole cause?

Agranulocytosis (potentially fatal).

Name a common gastrointestinal adverse effect of Methimazole.

Nausea and vomiting.

Which drug interaction can Methimazole have concerning anticoagulants?

Methimazole may increase the effects of anticoagulants like warfarin.

What should be monitored when a patient is on Methimazole?

CBC with differential for leukopenia or agranulocytosis, liver function tests, and thyroid function tests.

Why is it important for patients on Methimazole to report sore throat or fever?

These may be signs of agranulocytosis.

What lifestyle change should patients on Methimazole consider to avoid infection?

Avoid crowds or people who are sick.

What should patients on Methimazole be advised about taking their medication?

Take it consistently at the same time each day.

What should patients be aware of regarding stopping Methimazole?

Do not stop medication abruptly.

What signs might indicate the development of hypothyroidism while on Methimazole?

Fatigue, weight gain, and cold intolerance.

How should Methimazole be managed for patients undergoing treatment?

Monitor for signs of infection and report any unusual bleeding or bruising.