What's on this Page
Methimazole Brand Names- Northyx | Tapazole
What is Methimazole
Methimazole is an oral thioimidazole antithyroid agent.
Antithyroid agents are indicated for various hyperthyroid conditions including maintenance of a euthyroid state in patients with Graves’ disease until spontaneous remission occurs.
Methimazole is less likely to induce hepatotoxicity than propylthiouracil, especially in pediatric patients.
The drug is the preferred antithyroid agent for hyperthyroidism treatment when drug therapy must be used, except in the first trimester of pregnancy, where teratogenesis is a concern, or in cases of drug allergy or intolerance.
Methimazole was approved by the FDA in 1950.
Indications
- Graves’ disease
- hyperthyroidism
- thyrotoxicosis
For the treatment of hyperthyroidism, including Graves’ disease or toxic multinodular goiter when surgery or radioactive iodine therapy (RAI) is not appropriate, or for symptomatic treatment in preparation for thyroidectomy or RAI
Side Effects
- agranulocytosis
- alopecia
- anorexia
- aplastic anemia
- arthralgia
- bleeding
- drowsiness
- dysgeusia
- edema
- elevated hepatic enzymes
- exfoliative dermatitis
- fever
- headache
- hepatic encephalopathy
- hepatic necrosis
- hepatitis
- hypoglycemia
- hypoprothrombinemia
- hypothyroidism
- jaundice
- leukopenia
- lupus-like symptoms
- lymphadenopathy
- myalgia
- nausea
- nephrotic syndrome
- neuritis
- neutropenia
- pancytopenia
- paresthesias
- periarteritis
- peripheral neuropathy
- pruritus
- rash
- sialadenitis
- skin hyperpigmentation
- teratogenesis
- thrombocytopenia
- urticaria
- vasculitis
- vertigo
- vomiting
Monitoring Parameters
- CBC with differential
- LFTs
- thyroid function tests (TFTs)
Contraindications
- agranulocytosis
- aplastic anemia
- bone marrow suppression
- breast-feeding
- geriatric
- hepatic disease
- hepatitis
- hepatotoxicity
- jaundice
- leukopenia
- neutropenia
- pregnancy
- serious rash
- thrombocytopenia
- vasculitis
Interactions
- Acebutolol
- Amiodarone
- Atenolol
- Atenolol; Chlorthalidone
- Bendroflumethiazide; Nadolol
- Beta-blockers
- Betaxolol
- Bisoprolol
- Bisoprolol; Hydrochlorothiazide, HCTZ
- Brimonidine; Timolol
- Carteolol
- Carvedilol
- Deferiprone
- Digoxin
- Dorzolamide; Timolol
- Esmolol
- Hydrochlorothiazide, HCTZ; Metoprolol
- Hydrochlorothiazide, HCTZ; Propranolol
- Iodine; Potassium Iodide, KI
- Iodoquinol
- Labetalol
- Levobetaxolol
- Levobunolol
- Macimorelin
- Metoprolol
- Nadolol
- Nebivolol
- Nebivolol; Valsartan
- Penbutolol
- Pindolol
- Potassium Iodide, KI
- Propranolol
- Sodium Iodide
- Sotalol
- Theophylline, Aminophylline
- Thyroid hormones
- Timolol
- Warfarin