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Propylthiouracil

Generic Name: propylthiouracil (PRO pil THYE oh URE a sil)
Brand Name:

Medically reviewed by Drugs.com on Nov 1, 2018 – Written by Cerner Multum

What is propylthiouracil?

Propylthiouracil is used to treat hyperthyroidism (overactive thyroid), Graves' disease, or toxic goiter (enlarged thyroid). propylthiouracil is sometimes given to control symptoms just before you undergo thyroid surgery or treatment with radioactive iodine.

Propylthiouracil is for use only if your condition cannot be treated with another thyroid medication, or when surgery or radioactive iodine are not good treatment options.

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

Important Information

Propylthiouracil can cause liver problems that can be fatal or may require a liver transplant. Stop taking this medicine and call your doctor right away if you have signs of liver damage: fever, itching, tiredness, nausea, vomiting, upper stomach pain, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Do not use propylthiouracil if you are pregnant.

Before taking this medicine

You should not use propylthiouracil if you are allergic to it.

Tell your doctor if you have ever had liver problems.

Do not use propylthiouracil if you are pregnant, and tell your doctor right away if you become pregnant. Propylthiouracil can harm an unborn baby, or cause serious liver problems or death of the baby or the mother. You may need to use another medication during late pregnancy.

It may not be safe to breast-feed while using propylthiouracil. Ask your doctor about any risk.

In most cases, propylthiouracil should not be used by anyone younger than 18 years old. Do not give propylthiouracil to a child without your doctor's advice.

How should I take propylthiouracil?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Propylthiouracil is usually taken 3 times per day.

You will need frequent blood tests to check your thyroid function.

Call your doctor if you have unusual bruising or bleeding, or signs of infection (fever, chills, sore throat).

If you need surgery, tell your surgeon you currently use propylthiouracil.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Get your prescription refilled before you run out of medicine completely.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include fever, chills, itching, upset stomach, nausea, vomiting, swelling, headache, or joint pain.

What should I avoid while taking propylthiouracil?

Avoid driving or hazardous activity until you know how propylthiouracil will affect you. Your reactions could be impaired.

Propylthiouracil side effects

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Propylthiouracil can cause liver damage (especially during the first 6 months of treatment). Liver failure can be fatal or may require a liver transplant. Stop taking propylthiouracil and call your doctor right away if you have signs of liver damage:

  • nausea, vomiting, upper stomach pain;

  • itching;

  • fever, tiredness;

  • loss of appetite;

  • dark urine, clay-colored stools; or

  • jaundice (yellowing of the skin or eyes).

Also call your doctor at once if you have:

  • fever, chills, sore throat, mouth sores, feeling light-headed;

  • unusual bleeding;

  • purple or red discoloration of your skin;

  • skin rash, skin pain or swelling;

  • pink or dark urine, foamy urine, little or no urination;

  • shortness of breath, or if you cough up blood; or

  • new or worsening symptoms of lupus--joint pain, and a skin rash on your cheeks or arms that worsens in sunlight.

Common side effects may include:

  • nausea, vomiting, stomach pain;

  • itching or tingling;

  • joint or muscle pain;

  • swollen glands;

  • headache, drowsiness, dizziness;

  • swelling in your hands or feet;

  • decreased sense of taste; 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.

Propylthiouracil dosing information

Usual Adult Dose for Hyperthyroidism:

-INITIAL DOSE: 100 mg orally every 8 hours (300 mg daily); some patients may require 400 mg orally daily in 3 divided doses; rarely, a patient may require 600 to 900 mg orally daily in 3 divided doses
-MAINTENANCE DOSE: 100 to 150 mg orally daily in 3 equally divided doses every 8 hours

Use: In patients with Graves' disease with hyperthyroidism or toxic multinodular goiter who are intolerant of methimazole and for whom surgery or radioactive iodine therapy is not an appropriate treatment option

Usual Adult Dose for Thyroid Storm:

-INITIAL DOSE: 100 mg orally every 8 hours (300 mg daily); some patients may require 400 mg orally daily in 3 divided doses; rarely, a patient may require 600 to 900 mg orally daily in 3 divided doses
-MAINTENANCE DOSE: 100 to 150 mg orally daily in 3 equally divided doses every 8 hours

Use: To ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy in patients who are intolerant of methimazole

Usual Pediatric Dose for Hyperthyroidism:

This drug is generally not recommended for use in pediatric patients except when other therapies are not an option.
SUGGESTED INITIAL DOSE:
-Patients younger than 6 years: Not recommended
-Patients 6 years or older: 50 mg orally daily with careful upward titration based on clinical response and evaluation of TSH and free T4 levels

Comment:
-Although cases of severe liver injury have been reported with doses as low as 50 mg per day, most cases were associated with doses of 300 mg per day and higher.

Use: Hyperthyroidism

What other drugs will affect propylthiouracil?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may affect propylthiouracil, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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