Medicines & Supplements A to Z > Methimazole


Last updated on 13/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  

GENERIC NAME: Methimazole




DRUG CLASS: Endocrine drugs

SUB CLASS: Thioamides

USED FOR: Hyperthyroidism


What is Methimazole for?

Methimazole is a type of thioamide antithyroid agent. It works by reducing the level of thyroid hormone produced and secreted to treat hyperthyroidism in patients with Graves’ disease for whom surgery or radioactive iodine therapy is not an appropriate treatment option.

How to use it?

Methimazole is taken orally as tablets. The usual initial dose should be individualized by professionals based on laboratory results. The usual maintenance dose is 5-10 mg daily. Adjustments can be made upon laboratory results.

What are the side effects of Methimazole?

Common side effects of Methimazole include headache, edema, fever, skin rash, nausea, vomiting, and arthralgia. 

Who should not take Methimazole?

People who are allergic to Methimazole or any component of the formulation.

Pharmacist Tips:

– This drug may cause serious blood side effects. Report any symptoms such as fever or sore throat immediately, and have regular blood tests.
– Tell your doctor if you are pregnant or planning to get pregnant before using this drug. 

Common dosing schedule:
Methimazole can be taken with or without food.

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Methimazole may interact with:
– Beta-blockers, e.g. Propranolol, Metoprolol

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Methimazole in Hong Kong?

In Hong Kong, Methimazole is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Methimazole in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.