Methimazole is a drug to treat hyperthyroidism, which is a condition of high thyroid hormone levels. One of the causes of hyperthyroidism is Graves ' disease ( Graves ' disease) . This drug can also be used before patients undergo thyroid surgery or radioactive iodine therapy.

Methimazole belongs to the class of antithyroid drugs. This drug works by inhibiting the work of the thyroid gland in producing thyroid hormone. That way, thyroid hormone levels can decrease and symptoms of hyperthyroidism, such as palpitations or tremors, can subside.

Methimazole trademarks: -

What is Methimazole

class Prescription drug
Category Antithyroid
Benefit Overcoming hyperthyroidism
Consumed by Adults and children
Methimazole for pregnant and lactating women


Category D: There is positive evidence of risk to the human fetus, but the benefits may outweigh the risks, for example in dealing with a life-threatening situation.

Methimazole can be absorbed into breast milk. If you are breastfeeding, do not use this medicine without consulting your doctor first.

Drug form Tablet

Precautions Before Taking Methimazole

There are several things that you should pay attention to before taking methimazole, including:

  • Tell your doctor about any history of allergies you have. Methimazole should not be used by patients who are allergic to this drug.
  • Tell your doctor if you have or currently have liver disease , a weakened immune system, pancreatitis , a blood disorder, such as angranulocytosis or aplastic anemia .
  • Tell your doctor if you are pregnant, breastfeeding or planning a pregnancy.
  • If you are planning to have surgery or certain medical procedures, tell your doctor that you are currently taking methimazole.
  • Tell your doctor if you are taking certain medications, supplements or herbal products.
  • See a doctor immediately if you have an allergic drug reaction , serious side effects, or an overdose after taking methimazole.

Dosage and Rules for Use of Methimazole

The dose of methimazole varies for each patient. The doctor will adjust the dose according to the patient's age and health condition. Here is the explanation:

Condition: Hyperthyroidism

  • Adult: For mild hyperthyroidism, the dose is 15 mg per day divided into 3 times. For moderate hyperthyroidism, the dose is 30–40 mg per day divided into 3 times. For severe conditions the dose is 60 mg per day which is divided into 3 times. Maintenance dose 5–30 mg daily in 3 divided doses.
  • Children: Initially 0.5–0.7 mg/kg per day in 3 divided doses Maintenance dose 0.2 mg/kg per day in 3 divided doses.

Condition: Graves' disease

  • Adult: 10–20 mg per day. The dose may be reduced by up to 50% of the initial dose when thyroid hormone levels return to normal. Treatment can be done for 12-18 months.

How to Take Methimazole Correctly

Take methimazole as directed by your doctor and always read the instructions for use listed on the drug packaging. Do not reduce or increase your dose without consulting your doctor first.

Methimazole should be taken with food to reduce nausea. Use plain water to swallow the tablets.

If you forget to take methimazole, take it as soon as you remember. If it is nearing time for your next dose, skip the missed dose. Do not double the dose of methimazole to make up for a missed dose.

Store methimazole at room temperature and place it in a closed container. Avoid exposure to direct sunlight and keep out of reach of children.

Methimazole Interactions with Other Drugs

The following are a number of interactions that can occur when methimazole is used together with other drugs:

  • Increases the risk of bleeding if taken with anticoagulant drugs, such as warfarin
  • Increased risk of liver damage when used with teriflunomide, pexidartinib or lopitamide
  • Decrease the effectiveness of beta-blockers , such as atenolol , sotalol, or labetalol
  • Increase blood levels of theophylline or digoxin

Side Effects and Dangers of Methimazole

Some of the side effects that can arise after taking methimazole are:

  • Muscle pain and joint pain
  • The appearance of a rash on the skin
  • Hair loss
  • Headache, dizziness, or drowsiness
  • Nausea and vomiting
  • Stomach ache
  • pins and needles
  • Loss of ability to taste

Check with your doctor if the complaints mentioned above do not go away or get worse. Immediately see a doctor if you experience an allergic drug reaction or experience more serious side effects, such as:

  • Headache that gets worse or vertigo that doesn't get better
  • Coughing up blood or difficulty breathing
  • Kidney disorders , which may be characterized by infrequent or very small amounts of urine
  • Decreased production of blood cells which can increase the risk of infection or anemia
  • Impaired liver function, which can be characterized by complaints of jaundice , dark urine, severe stomach pain , or severe nausea and vomiting that doesn't go away
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