Tapazole

DRUG DESCRIPTION

Tapazole® (Methimazole Tablets, USP) (1-methylimidazole-2-thiol) is a white, crystalline substance that is freely soluble in water. It differs chemically from the drugs of the thiouracil series primarily because it has a 5- instead of a 6-membered ring.

Each tablet contains 5 or 10 mg (43.8 or 87.6 ?mol) methimazole, an orally administered antithyroid drug.

Each tablet also contains lactose monohydrate, magnesium stearate, starch (corn), pregelatinized starch and talc.

The molecular weight is 114.16, and the molecular formula is C4H6N2S. The structural formula is as follows:

TAPAZOLE (methimazole) Structural Formula Illustration

What are the possible side effects of methimazole (Northyx, Tapazole)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop taking methimazole and call your doctor at once if you have any of these serious side effects:

  • fever, chills, sore throat, body aches, flu symptoms;
  • easy bruising or bleeding, unusual weakness;
  • blood in your urine or stools;
  • severe blistering, peeling, and red skin rash; or
  • nausea, stomach pain, low fever,...

Read All Potential Side Effects and See Pictures of Tapazole »

What are the precautions when taking methimazole (Tapazole)?

Before taking methimazole, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: blood disorders (such as agranulocytosis, thrombocytopenia), liver disease.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This medication is not recommended for use during the first 3 months of pregnancy. It should be used only when clearly needed during the last 6 months of pregnancy. Discuss the...

Read All Potential Precautions of Tapazole »


Tapazole Consumer (continued)

SIDE EFFECTS: Stomach upset, nausea, vomiting, or mild rash/itching may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these rare but serious side effects occur: yellowing eyes/skin, dark urine, severe stomach/abdominal pain, persistent nausea/vomiting, joint/muscle pain, change in the amount of urine.

This medication may rarely cause very serious blood disorders (such as a low number of red cells, white cells, and platelets), especially during the first few months of treatment. Tell your doctor immediately if you develop any of the following symptoms: signs of infection (such as fever, persistent sore throat), easy bruising/bleeding, unusual tiredness.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking methimazole, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: blood disorders (such as agranulocytosis, thrombocytopenia), liver disease.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This medication is not recommended for use during the first 3 months of pregnancy. It should be used only when clearly needed during the last 6 months of pregnancy. Discuss the risks and benefits with your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, contact your doctor immediately.

This medication passes into breast milk. Consult your doctor before breast-feeding.


Tapazole Patient Information Including Side Effects

Brand Names: Northyx, Tapazole

Generic Name: methimazole (Pronunciation: me THIM a zole)

  • What is methimazole (Tapazole)?
  • What are the possible side effects of methimazole (Tapazole)?
  • What is the most important information I should know about methimazole (Tapazole)?
  • What should I discuss with my healthcare provider before taking methimazole (Tapazole)?
  • How should I take methimazole (Tapazole)?
  • What happens if I miss a dose (Tapazole)?
  • What happens if I overdose (Tapazole)?
  • What should I avoid while taking methimazole (Tapazole)?
  • What other drugs will affect methimazole (Tapazole)?
  • Where can I get more information?

What is methimazole (Tapazole)?

Methimazole prevents the thyroid gland from producing too much thyroid hormone.

Methimazole is used to treat hyperthyroidism (overactive thyroid). It is also used before thyroid surgery or radioactive iodine treatment.

Methimazole may also be used for other purposes not listed in this medication guide.

What are the possible side effects of methimazole (Tapazole)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop taking methimazole and call your doctor at once if you have any of these serious side effects:

  • fever, chills, sore throat, body aches, flu symptoms;
  • easy bruising or bleeding, unusual weakness;
  • blood in your urine or stools;
  • severe blistering, peeling, and red skin rash; or
  • nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

  • headache, drowsiness, dizziness;
  • mild nausea, vomiting, or stomach upset;
  • itching, minor skin rash;
  • muscle, joint, or nerve pain;
  • swelling; or
  • hair loss.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about methimazole (Tapazole)?

Do not take methimazole if you are breast-feeding a baby.

Do not use this medication without telling your doctor if you are pregnant. It could cause harm to the unborn baby. Use an effective form of birth control, and tell your doctor if you become pregnant during treatment.

Methimazole can increase your risk of bleeding. If you need to have surgery, tell the surgeon ahead of time that you are using this medication.

Methimazole can lower the blood cells that help your body fight infections. This can make it easier for you to get sick from being around others who are ill. To be sure your blood cells do not get too low, your blood will need to be tested on a regular basis. Do not miss any scheduled visits to your doctor.

Do not receive a "live" vaccine while you are being treated with methimazole, and avoid coming into contact with anyone who has recently received a live vaccine. There is a chance that the virus could be passed on to you.

Keep using this medication even if you feel fine or have no symptoms of hyperthyroidism. You may need to keep taking methimazole long term to control your condition. Stopping the medication could cause your symptoms to return.

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