What is Methimazole?

The thyroid system is one of the most important systems in the human body that plays a vital role in controlling metabolic function and general health. Thyroid disorders, including hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid), can lead to serious health problems. One of the key drugs used as an important tool in the management of thyroid disorders is methimazole. When the thyroid gland is overactive or underactive, the patient experiences annoying symptoms that require treatment with this drug. In the following, we will examine the medicinal forms, uses, precautions and contraindications of methimazole.

Pharmaceutical forms of methimazole

The dosage forms of methimazole include tablets of 5 mg and 10 mg. The doctor prescribes different forms of this medicine by examining the type of disorder or disease, the patient’s age, etc.

Uses of methimazole tablets

Methimazole is used to treat hyperthyroidism, a condition that occurs when the thyroid gland produces too much thyroid hormone. Radioactivity should also be taken before thyroid surgery or treatment. This medicine can be used for other purposes with the approval and prescription of a doctor. Some of the most important uses of this drug include hyperthyroidism, Graves’ disease, thyrotoxicosis (off-label) and…

Uses of methimazole in adults

1. Graves’ disease
2. thyrotoxicosis (off label)
3. hyperthyroidism

Uses of methimazole in children

1. Graves’ disease
2. thyrotoxicosis (off label)
3. hyperthyroidism

Pharmacological effects and mechanism of action of methimazole drug

The mechanism of action of methimazole inhibits thyroid hormone synthesis by blocking iodine oxidation in the thyroid gland. It also blocks the synthesis of thyroxine (T4) and triiodothyronine (T3). Absorption with bioavailability of 80-95% and the onset of PO is 12-18 hours in a period of 36-72 hours. This drug is metabolized by the liver and finally excreted through the urine.

Dosage of methimazole

Take methimazole tablets orally with a glass of water. You can also take this medicine with or without food. Before using, carefully read the drug information (how to use) on the drug packaging. However, you should always take it in the same way to ensure that the effects are the same. Take your medication at regular intervals and do not exceed the time prescribed on the prescription or on the medication label. This medicine can be used in children only with a doctor’s prescription and approval.

Time to take methimazole tablets

Dosage is based on your medical condition and response to treatment, and for children, the dosage is based on their weight. Do not increase, decrease or stop your dose without consulting your doctor. Use this medicine regularly to get the most benefit from it. Take it at the same times every day to help you remember. If your condition does not improve or worsens, tell your doctor.

How to take methimazole tablets in adults

1. Methimazole drug is prescribed for the treatment of mild hyperthyroidism 15 mg daily initially every 8 hours, moderate hyperthyroidism 30-40 mg orally every 8 hours, severe hyperthyroidism 60 mg daily orally every 8 hours.
2. For Graves’ disease, 10-20 mg orally once a day, reduce the dose by 50% after developing thyroidism and prescribe for 12-18 months. If the TSH level is normal, the dose may subsequently be reduced or stopped.
3. Thyrotoxicosis (off-label), 15-20 mg orally every 4 hours during the day, first prescribed as an adjunct to other agents. Also, if the patient is stable, reduce the medication to every 12 hours or once a day.

How to use methimazole tablets in children

1. For the treatment of hyperthyroidism in children, 0.7-5 mg/kg per day is used in divided doses of 8 hours. To treat this disease, the total amount of consumption should not exceed 30 mg per day.
2. Graves’ disease 0.5-2 mg/kg daily orally, reduce the dose by 50% after developing thyroidism and administer for 1-2 years.
3. Thyrotoxicosis (off-label) 1-5 mg/kg daily is used orally. Also, adjust subsequent doses and duration of treatment based on patient response.

Precautions

Before taking methimazole, if you are allergic to it, consult your doctor or pharmacist so that they can prescribe similar drugs for you if needed. This medicine may contain inactive ingredients that can cause allergic reactions or other problems. Patients with specific medical records such as blood disorders (agranulocytosis, thrombocytopenia), liver disease, pancreatitis, severe liver or kidney disorder, etc. should consult a doctor regarding the risks of using this medicine. It is also not recommended to use this medicine in the first 3 months of pregnancy.

1. Hypoprothrombinemia and bleeding may occur after taking methimazole.
2. Antineutrophil cytoplasmic antibody (ANCA) positive vasculitis has been reported. Discontinue use if vasculitis is present.
3. Long-term treatment may cause hypothyroidism. Monitor free T4 and TSH levels routinely and adjust dosage as necessary to maintain thyroid status.
4. In some patients, significant bone marrow suppression occurs. Use caution if co-administered with other drugs that suppress myeloscopy. Discontinue use if significant agranulocytosis, leukopenia, or aplastic anemia occurs.
5. reported hepatitis; In case of occurrence or if the level of clinically significant liver enzymes, including transaminases, is more than 3 times the upper limit of normal, the drug should be stopped.
6. Antithyroid agents associated with rare but severe skin reactions; Discontinue use if peeling dermatitis occurs.
7. Tell your doctor and pharmacist what prescription and over-the-counter medications you are taking, especially anticoagulants (blood thinners) such as warfarin (Coumadin), beta-blockers such as propranolol (Inderal), diabetes medications, digoxin (Lanoxin), theophylline (Theobid). , Theo-Dur) and vitamins
8. Tell your doctor if you have a blood disorder such as low white blood cells (leukopenia), low platelets (thrombocytopenia), aplastic anemia, or liver disease (hepatitis, jaundice).
9. Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding. Methimazole should not be used during pregnancy or breastfeeding. If you become pregnant while taking methimazole, call your doctor right away.

Contraindications for methimazole

1. Hypersensitivity
2. Breastfeeding a baby or pregnancy (during pregnancy only with a doctor’s prescription and approval)

Side effects of methimazole

Alopecia, aplastic anemia, skin reactions (for example, skin rashes, itching, skin pigmentation), liver toxicity, neuritis, polyarthritis, itching, salivary gland swelling, dizziness, etc. are some of the side effects of methimazole. If any of these effects persist or worsen, tell your doctor or pharmacist right away. Some of the serious side effects of this drug include joint or muscle pain, numbness and tingling of the skin, shortness of breath, coughing up blood, symptoms of liver problems, etc. If these cases occur, stop taking the medicine and see a doctor.

1. Agranulocytosis
2. alopecia
3. Aplastic anemia
4. Skin reactions (rash, itching, skin pigmentation)
5. Hepatotoxicity
6. Leukocytoclastic vasculitis
7. neuritis
8. polyarthritis
9. itching
10. Swelling of the salivary glands
11. Skin pigments
12. Thrombocytopenia
13. urticaria
14. dizziness

Methimazole drug interactions

1. Class X interactions (avoidance): BG (intravesical), cladribine, dipyrone, acenocoumarol, anisindione, dicoumarol, phenidion, phenprocoumon, warfarin
2. Reduction of the effects of drugs by methimazole: BG (intravesical), prednisolone (systemic), sodium iodide I131, vitamin K antagonists
3. Increasing the effects of drugs by methimazole: cardiac glycosides, clozapine, deferiprone, theophylline derivatives.
4. Increased effects of methimazole by drugs: chloramphenicol (ophthalmic), cladribine, dipyrone, mesalamine, promazine.

Use of methimazole during pregnancy and breastfeeding

Using this medicine in the first three months of pregnancy can harm your fetus. Use an effective method of contraception to prevent pregnancy. If you think you have become pregnant while using this medicine, tell your doctor right away. Specific information regarding the presence of this drug in human milk is not available.

Methimazole storage conditions

Methimazole should be stored at room temperature and away from light. It is also important to keep all medications out of the reach of children, as many forms of medication (such as weekly tablets and eye drops, creams, patches, and inhalers) are not child-resistant and can be easily opened by young children. . Unnecessary medications should be disposed of in specific ways to ensure that pets, children, and other people cannot ingest them.

The last word of methimazole

In this article from the online positive pharmacy magazine, we investigated the role of methimazole in the treatment of thyroid disorders. Thyroid is one of the vital systems of the human body, and its disorders can lead to serious health problems. This drug serves as a key tool in the management of thyroid disorders, especially in cases of hyperthyroidism (overactive thyroid). This drug can help control the unwanted increase in thyroid activity by inhibiting the thyroid activity and the production of thyroid hormones. By taking methimazole, it is possible to control the symptoms and complications of thyroid disorders, improve the quality of life of patients and reduce the risks associated with these disorders. We have described this article titled Methimazole drug from Positive Green online pharmacy magazine.

Site source: Medscapee