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Propylthiouracil Tablets

Propylthiouracil is a medication that decreases the amount of thyroid hormone your thyroid hormone makes. It treats a condition that causes your thyroid gland to produce too much of the hormone called hyperthyroidism. This medication comes in a tablet form.

What is this medication?

PROPYLTHIOURACIL (proe pill thye oh YOOR a sill), or PTU, treats high thyroid levels (hyperthyroidism) in your body. It works by decreasing the amount of thyroid hormone your body makes.

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This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Liver disease
  • Low blood cell levels, such as low white cell levels
  • An unusual or allergic reaction to propylthiouracil, other medications, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth. Take it as directed on the prescription label at the same time every day. Keep taking it unless your care team tells you to stop.

A special MedGuide will be given to you by the pharmacist with each prescription and refill. Be sure to read this information carefully each time.

Talk to your care team about the use of this medication in children. While it may be prescribed for children as young as 6 years for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

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What may interact with this medication?

  • Aminophylline
  • Certain medications for blood pressure, heart disease, irregular heartbeat
  • Certain medications that prevent or treat blood clots, such as warfarin
  • Digoxin
  • Theophylline

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse. It may be some time before you see the benefit from this medication.

You may need blood work done while you are taking this medication.

Biotin (vitamin B7) may interfere with your thyroid function test. Stop taking supplements that contain biotin 2 days before your blood work.

This medication may increase your risk of getting an infection. Call your care team for advice if you get a fever, chills, sore throat, or other symptoms of a cold or flu. Do not treat yourself. Try to avoid being around people who are sick.

Talk to your care team if you may be pregnant. Serious birth defects can occur if you take this medication during pregnancy.

If you are going to need surgery or a procedure, tell your care team that you are taking this medication.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • Aplastic anemia—unusual weakness or fatigue, dizziness, headache, trouble breathing, increased bleeding or bruising
  • Infection—fever, chills, cough, or sore throat
  • Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
  • Low thyroid levels (hypothyroidism)—unusual weakness or fatigue, increased sensitivity to cold, constipation, hair loss, dry skin, weight gain, feelings of depression
  • Unusual bruising or bleeding
  • Unusual weakness or fatigue, fever, headache, skin rash, muscle or joint pain, loss of appetite, pain, tingling, or numbness in the hands or feet

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Change in taste
  • Drowsiness
  • Hair loss
  • Headache
  • Nausea
  • Swelling of the ankles, hands, or feet

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

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Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Keep the container tightly closed. Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

  • Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
  • If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, empty the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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