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Thiamazole

Thiamazole is an antithyroid medicine. It is used to treat hyperthyroidism, a condition in which the thyroid gland produces more thyroid hormone than the body needs. Thiamazole belongs to the thionamide group of drugs. It is taken by mouth as a tablet.

Medicine containing Thiamazole

Tapazole

Hyperthyroidism

5 · 10mg

Tapazole contains thiamazole and is a tablet used for hyperthyroidism. It comes in several strengths and pack sizes. You can compare the price per tablet across options.

FromUS$0.48/ tabletView

Key points

  • Thiamazole starts to act within 30 to 60 minutes, and its effect lasts about 6 to 12 hours.
  • It is also taken before surgery on the thyroid gland or radioactive iodine treatment, to prepare the gland for those procedures.
  • Blood tests during treatment track thyroid hormone levels and white blood cell counts, so that serious reactions are found early.

What thiamazole is used for

The main use is hyperthyroidism, where an overactive gland drives metabolic activity too high. Treatment lowers hormone output so that levels in the blood move back towards normal. Thiamazole is also given ahead of surgery on the thyroid or radioactive iodine treatment. In children it is used with a doctor’s supervision. It is one of the medicines used in thyroid health care.

How it works

Thiamazole blocks thyroid peroxidase, the enzyme that attaches iodine to tyrosine residues inside the thyroid gland. Without this step, the gland cannot build thyroid hormones, so the amount of active hormone released into the blood falls.

Forms and brands

Tapazole tablets contain thiamazole in 5 mg and 10 mg strengths and are used for hyperthyroidism. Tablets are the only form. Pharmacy partners in India ship orders to Malaysia in discreet packaging.

Safety

Thiamazole must not be used by anyone with a hypersensitivity to thionamides, severe hepatic impairment, or a history of bone marrow disorders. Because it can depress the bone marrow, any sign of infection or a sore throat should be reported immediately, and white blood cell counts are monitored during treatment. Use in pregnancy needs medical advice, since risk is associated with first-trimester use.

Common effects include nausea, rash, arthralgia and headache. Jaundice and pruritus are more serious and need review. Agranulocytosis, hepatitis and vasculitis are serious and require immediate medical attention. Thiamazole interacts with warfarin and theophylline.

What the sources say

  • A severe liver disorder or a serious blood disorder rules out treatment with this medicine (Carbimazole PIL).
  • A past episode of acute pancreatitis after carbimazole or thiamazole is a contraindication (Carbimazole PIL).
  • Breast-feeding is contraindicated, as small amounts may pass into the mother’s milk (Carbimazole PIL).
  • Reliable contraception should be used from the start of treatment and throughout, because the medicine can harm an unborn baby (Carbimazole PIL).

Further reading

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