Medication Quick Search
My Medicine List Your Hospital Pharmacist Medication Tips and Tools

Propylthiouracil

(proe pill thye oh yoor' a sill)

Brand Name(s): Propycil; also available generically

Other Name(s): PTU

IMPORTANT WARNING:

Propylthiouracil may cause severe liver damage in adults and children. Some people who took propylthiouracil needed liver transplants and some people died because of the liver damage. Because of this risk, propylthiouracil should only be given to people who cannot receive other treatments such as surgery, radioactive iodine, or a different medication called methimazole (Tapazole). Propylthiouracil may also be given to women during the first months (about 12 weeks) of pregnancy because methimazole may cause birth defects if it is used during this part of a pregnancy.

If you are taking propylthiouracil, call your doctor immediately if you develop any of the following symptoms: fever, loss of appetite, nausea, vomiting, tiredness, itching, dark urine, pale or light colored stools, yellowing of the skin or eyes, or pain in the upper right part of the stomach.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with propylthiouracil and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm).

WHY is this medicine prescribed?

Propylthiouracil is used to treat hyperthyroidism (a condition that occurs when the thyroid gland produces too much thyroid hormone, speeding the body's metabolism, and causing certain symptoms) in adults and children 6 years of age or older. Propylthiouracil is in a class of medications called antithyroid agents. It works by stopping the thyroid gland from making thyroid hormone.

Are there OTHER USES for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

HOW should this medicine be used?

Propylthiouracil comes as a tablet to take by mouth. It is usually taken three times a day, once every 8 hours. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take propylthiouracil exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor may decrease your dose of propylthiouracil once your condition is controlled.

Continue to take propylthiouracil even if you feel well. Do not stop taking propylthiouracil without talking to your doctor.

What SPECIAL PRECAUTIONS should I follow?

Before taking propylthiouracil,

  • tell your doctor and pharmacist if you are allergic to propylthiouracil, any other medications, or any of the ingredients in propylthiouracil tablets. Ask your doctor or pharmacist or check the Medication Guide for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin), beta blockers such as atenolol (Tenormin), labetalol (Normodyne), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), and propranolol (Inderal); digoxin (Digitek, Lanoxin), and theophylline (Theo-24, Theochron, Theolair). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with propylthiouracil, so be sure to tell your doctor about all the other medications you are taking, even if they do not appear on this list.
  • tell your doctor if you have or have ever had leukopenia (decreased white blood cells) , thrombocytopenia (decreased platelets), or aplastic anemia (condition in which the body does not make enough new blood cells), or other conditions that cause low numbers of red blood cells, white blood cells, or platelets; or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking propylthiouracil, call your doctor.Your doctor may tell you to take propylthiouracil during the first months of your pregnancy only and then may switch you to methimazole for the rest of your pregnancy. Propylthiouracil may cause severe liver problems in pregnant women and may harm the fetus.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking propylthiouracil.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Propylthiouracil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • hair loss
  • difficulty tasting food
  • numbness, burning, or tingling of the hands or feet
  • joint or muscle pain
  • dizziness
  • swelling of the neck

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

  • sore throat, fever, chills, cough, or other signs of infection
  • headache
  • skin rash, hives, blisters, bumps or peeling
  • dark, rust-colored, brown or foamy urine
  • swelling of the face, eyes, stomach, arms, hands, feet, ankles, or lower legs
  • chest pain
  • shortness of breath or wheezing
  • coughing up blood

Propylthiouracil may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

  • nausea
  • vomiting
  • stomach pain
  • headache
  • fever
  • joint pain
  • itching
  • swelling of the hands, arms, feet, ankles, or lower legs
  • sore throat, fever, chills, and other signs of infection
  • unusual bruising or bleeding
  • blistering or peeling of the skin
  • numbness, burning or tingling of the hands or feet
  • yellowing of the skin or eyes
  • loss of appetite
  • pain in the upper right part of the stomach
  • itching
  • unusual bruising or bleeding
  • excessive tiredness
  • weakness

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to propylthiouracil.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

This branded product is no longer on the market. Generic alternatives may be available.


This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists® represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists® makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists® does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

Pronunciation Guide for Drug Names is used with permission. © 2009. The United States Pharmacopeial Convention. All Rights Reserved.

AHFS® Patient Medication Information™. © Copyright, 2020. The American Society of Health-System Pharmacists®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: July 15, 2017.