Propylthiouracil (PTU)


Generic Name: Propylthiouracil (PTU) Brand Name(s): Generics only. No brands available.


What is propylthiouracil used for?

Propylthiouracil is an antithyroid agent. It works by reducing the formation of thyroid hormones by the thyroid gland.

It is commonly used for treating an overactive thyroid gland in certain patients. It may be used to prepare the thyroid gland for surgery or treatment with radioactive iodine, as well as when surgery to remove the thyroid gland is not an option. It may also be used for other conditions as determined by your doctor.

How should I take propylthiouracil?

Use propylthiouracil as directed by your doctor. Check the label on the medicine for exact dosing instructions.

Take propylthiouracil by mouth with or without food.

Unless directed otherwise by your doctor, space your doses evenly throughout the day.

Ask your health care provider any questions you may have about how to use propylthiouracil.

How do I store propylthiouracil?

Propylthiouracil is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store propylthiouracil in the bathroom or the freezer. There may be different brands of propylthiouracil that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush propylthiouracil down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using propylthiouracil?

Before using this drug, tell your doctor if:

  • You are allergic to any ingredient in propylthiouracil.
  • You are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement.
  • You have allergies to medicines, foods, or other substances.

Is it safe during pregnancy or breastfeeding?


Propylthiouracil has been shown to cause harm to the fetus. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using propylthiouracil while you are pregnant.


Propylthiouracil is found in breast milk. If you are or will be breastfeeding while you use propylthiouracil, check with your doctor. Discuss any possible risks to your baby.

Side effects

What side effects can occur from propylthiouracil?

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most common side effects persist or become bothersome:

  • Dizziness
  • Drowsiness
  • Headache
  • Mild hair loss
  • Mild muscle pain
  • Taste changes or loss

Seek medical attention right away if any of these severe side effects occur:

  • Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue)
  • Change in amount of urine
  • Coughing up blood
  • Joint pain
  • Red, swollen, blistered, or peeling skin
  • Shortness of breath
  • Skin numbness or tingling
  • Swollen or painful lymph nodes
  • Symptoms of infection (e.g., fever, chills, sore throat, cough, severe or persistent headache)
  • Symptoms of liver problems (e.g., dark urine; loss of appetite; pale stools; severe or persistent nausea, stomach pain, or vomiting; yellowing of the skin or eyes)
  • Unusual bleeding or bruising
  • Unusual swelling
  • Unusual or persistent tiredness or weakness

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with propylthiouracil?

Propylthiouracil may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products may interact with this drug, including:

  • Anticoagulants (e.g., warfarin)
  • Beta-blockers (e.g., propranolol)
  • Digoxin
  • Theophylline

Does food or alcohol interact with propylthiouracil?

Propylthiouracil may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with propylthiouracil?

Propylthiouracil may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

These health conditions are:

  • History of blood or bone marrow problems
  • Liver problems
  • Kidney problems
  • Lung or breathing problems


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using propylthiouracil.

What is the dose of propylthiouracil for an adult?

The initial adult dose of PTU is 300 mg/day divided into 3 divided doses. PTU is usually administered every eight hours. Patients with large goiters may require initial doses up to 900 mg daily. The usual long-term adult dose after initial treatment is 100-150 mg/day.

What is the dose of propylthiouracil for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is propylthiouracil available?

Propylthiouracil is available in the following dosage forms and strengths:

  • Tablet: 50 mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of propylthiouracil, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: February 6, 2017 | Last Modified: February 6, 2017