Methimazole

Description

Methimazole is used for the treatment of hyperthyroidism, a condition where the thyroid gland produces an excessive amount of thyroid hormones. It is also used to relieve the symptoms of hyperthyroidism before thyroid surgery or radioactive iodine treatment.

Side effects

Major & minor side effects for Methimazole

  • Back pain
  • Chest pain
  • Fever
  • Cough
  • Sore throat
  • Yellow eyes or skin
  • Nausea and vomiting
  • Rash

Uses of Methimazole

What is it prescribed for?

  • Hyperthyroidism
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Concerns

Commonly asked questions

  • Onset of action
    The effect of this medicine can be observed within 12 to 18 hours of administration of the dose.
  • Duration of effect
    The effect of this medicine lasts for an average duration of 36 to 72 hours.
  • Safe with alcohol?
    Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.
  • Is it habit forming?
    No habit-forming tendencies were reported.
  • Usage in pregnancy?
    This medicine is not recommended for use in pregnant women unless absolutely necessary. All the risks and benefits should be discussed with the doctor before taking this medicine.
  • Usage while breast-feeding?
    This medicine is not recommended for use in breastfeeding women unless absolutely necessary. All the risks and benefits should be discussed with the doctor before taking this medicine.

Allergy

This medicine is not recommended for use in patients with a known allergy to methimazole or any other inactive ingredients present along with it.
Warnings for special population

Pregnancy

This medicine is not recommended for use in pregnant women unless absolutely necessary. All the risks and benefits should be discussed with the doctor before taking this medicine.

Breast-feeding

This medicine is not recommended for use in breastfeeding women unless absolutely necessary. All the risks and benefits should be discussed with the doctor before taking this medicine.
General warnings

Hepatotoxicity

This medicine should be used with extreme caution in the patients suffering from liver diseases due to the increased risk of hepatotoxicity. Close monitoring of liver function tests is necessary while taking this medicine. Appropriate dose adjustments or replacement with a suitable alternative may be required in some cases based on the clinical condition.

Hypothyroidism

This medicine should be used with caution due to the increased risk of hypothyroidism (low thyroid hormone levels). This risk is especially higher if the medicine is used for a prolonged period of time. Close monitoring of thyroid function tests is necessary while receiving this medicine. Appropriate dose adjustments or replacement with a suitable alternative may be required in some cases based on the clinical condition.

Agranulocytosis

This medicine should be used with extreme caution in patients suffering from agranulocytosis, a condition that affects white blood cells, since it may worsen the patient's condition. Report to the doctor if you experience any unusual symptoms like fever, sore throat, shortness of breath, tiredness, pale skin, etc. immediately. Appropriate dose adjustments or replacement with a suitable alternative may be required in some cases based on the clinical condition.

Bleeding Disorders

This medicine should be used with extreme caution in patients suffering from bleeding disorders due to the increased risk of worsening of the patient's condition. Close monitoring of prothrombin time/INR is necessary while taking this medicine. Appropriate dose adjustment or replacement with a suitable alternative may be required in some cases based on the clinical condition.

Surgeries

This medicine should be used with extreme caution while planning for surgeries since it may cause excessive bleeding. Close monitoring of prothrombin time is necessary while taking this medicine. Appropriate dose adjustments or replacement with a suitable alternative may be necessary in some cases based on the clinical condition.

Missed Dose

The missed dose should be taken as soon as possible. It is advisable to skip the missed dose if it is already time for your next scheduled dose. Do not use extra medicine to make up for the missed dose.

Overdose

Seek emergency medical treatment or contact the doctor in case of an overdose.
All drugs interact differently for person to person. You should check all the possible interactions with your doctor before starting any medicine.
Interaction with Alcohol

Description

Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.

Instructions

Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.
Interaction with Medicine

Prednisolone

Leflunomide

Anticoagulants

Fluphenazine

Teriflunomide

Efavirenz

Clozapine

Carvedilol

Disease interactions

Liver Disease

This medicine should be used with caution in patients suffering from liver diseases or hepatitis due to the increased risk of hepatotoxicity. Close monitoring of liver functions tests is necessary while taking this medicine. Appropriate dose adjustments or replacement with a suitable alternative may be required in some cases based on the clinical condition.

Blood Dyscrasias

This medicine should be used with caution in patients suffering from blood dyscrasias (Thrombocytopenia, Neutropenia, leukopenia, etc.) since it may worsen the patient's condition. Regular monitoring of complete blood count levels is necessary while taking this medicine. Appropriate dose adjustments or replacement with a suitable alternative may be required in some cases based on the clinical condition.

Bleeding disorders

This medicine should be used with caution in patients suffering from an active bleeding disorder, hemorrhagic disorders, or clotting defects due to the increased risk of worsening of the patient's condition. Close monitoring of prothrombin time or INR is necessary while taking this medicine. Appropriate dose adjustments or replacement with a suitable alternative may be required in some cases based on the clinical condition.
Food interactions
Information not available.
Lab interactions
Information not available.
Take this medicine exactly advised by your doctor. Do not take in larger or smaller amounts than advised/prescribed. Consult the doctor if you experience any undesirable side effects. Ensure that the course of treatment is completed. Do not stop the use of this medicine without consulting your doctor.
Miscelleneous

To be taken with food

To be taken as instructed by doctor

May cause sleepiness

How it works
It inhibits the synthesis of thyroid hormone to reduce thyroid hormone levels and thus relieves associated symptoms.
Legal Status

Approved

Approved

Unknown

Unknown

Classification

Category

Antithyroid agents

Schedule

Schedule H

Methimazole [Internet]. Pubchem.ncbi.nlm.nih.gov. 2018 [cited 6 September 2018]. Available from:

https://pubchem.ncbi.nlm.nih.gov/compound/methimazole

[Internet]. Accessdata.fda.gov. 2018 [cited 6 September 2018]. Available from:

https://www.accessdata.fda.gov/drugsatfda_docs/label/2012/040350s016lbl.pdf

Methimazole - DrugBank [Internet]. Drugbank.ca. 2018 [cited 6 September 2018]. Available from:

https://www.drugbank.ca/drugs/DB00763

DailyMed - Methimazole tablet [Internet]. Dailymed.nlm.nih.gov. 2018 [cited 6 September 2018]. Available from:

https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4280e008-bbaf-4cc7-b588-3b4303016067

Methimazole: MedlinePlus Drug Information [Internet]. Medlineplus.gov. 2018 [cited 6 September 2018]. Available from:

https://medlineplus.gov/druginfo/meds/a682464.html

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Information on this page was last updated on 10 Jan 2019

Disclaimer

We’ve made all possible efforts to ensure that the information provided here is accurate, up-to-date and complete, however, it should not be treated as a substitute for professional medical advice, diagnosis or treatment. Practo only provides reference source for common information on medicines and does not guarantee its accuracy or exhaustiveness. The absence of a warning for any drug or combination thereof, should not be assumed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Practo does not assume any responsibility for any aspect of healthcare administered with the aid of information provided above. If you have any doubts about your medication then we strongly recommend that you consult with your doctor, nurse or healthcare provider. See detailed T&C here.