Methimazole (MMI) is used to treat hyperthyroidism and in preparation for surgery on an overactive thyroid. 


What is Methimazole?

Methimazole works by preventing the thyroid gland from producing too much thyroid hormone. 


How should Methimazole be taken?

Methimazole is taken orally, usually in the form of tablets. If it is taken on a full stomach, it reduces any gastric irritation.


Side effects associated with Methimazole

Among the possible of side effects of methimazole include the following:


  • Altered taste
  • Dizziness
  • Drowsiness
  • Headache
  • Articular pains
  • Feeling faint or lightheaded
  • Muscle aches
  • Nausea
  • Numbness or tingling
  • Stomach discomfort
  • Vomiting


You should contact your doctor immediately if you experience:


  • Rash
  • Urticaria
  • Difficulty breathing
  • Tightness in the chest
  • Swelling of the mouth, face, lips or tongue
  • Changes in appetite
  • Dark urine
  • Fainting
  • Fast or irregular heartbeat
  • Persistent fever, chills or sore throat
  • Severe or persistent headache, nausea or vomiting
  • Stomach ache
  • Tremors
  • Bleeding or bruising
  • Hair loss
  • Tiredness or weakness
  • Vision problems
  • Jaundice


Contraindications and warnings associated with the use of methimazole

Methimazole can compromise the ability to driver or operate dangerous machinery. This side effect may be further aggravated by alcohol and other drugs that cause drowsiness.


Before starting treatment with Methimazole, it is important to tell your doctor if:


  • You have any allergies to the active substance, its excipients or any other drugs or food
  • You are taking any other medications, herbal remedies or supplements. Mentioning in particular: anticoagulants, beta-blockers, digitalis glycosides, theophylline and corticosteroids
  • You are suffering (or have suffered) from bone marrow problems, liver problems or exfoliative dermatitis
  • You are pregnant or breast-feeding