What Is Propylthiouracil?
Propylthiouracil prevents the thyroid gland from producing too much thyroid hormone.
Propylthiouracil is used to treat hyperthyroidism (overactive thyroid), Graves’ disease, or toxic goiter (enlarged thyroid). This medicine 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 for you.
Propylthiouracil may also be used for other purposes not listed in this medication guide.
Propylthiouracil can cause liver damage in both adults and children. 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: fever, itching, 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.
You should not use propylthiouracil if you are allergic to it.
To make sure propylthiouracil is safe for you, tell your doctor if:
- you have liver problems;
- you have a weak immune system; or
- you need to have surgery.
Do not use propylthiouracil if you are pregnant, and tell your doctor right away if you become pregnant while using this medicine. Propylthiouracil can harm an unborn baby, or cause serious liver problems in the mother.
You may need to use another medication during pregnancy. Talk with your doctor if you plan to become pregnant while taking propylthiouracil.
Propylthiouracil can pass into breast milk and may harm a nursing baby. Do not use propylthiouracil while you are breast-feeding a baby.
In most cases, propylthiouracil should not be used by anyone younger than 18 years old. Do not give this medicine to a child without your doctor’s advice.
Propylthiouracil Side Effects
Propylthiouracil can cause liver damage in both adults and children (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;
- 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:
- easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;
- sudden chest pain or discomfort, wheezing, dry cough, feeling short of breath;
- little or no urination;
- low white blood cell counts–sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, red or swollen gums, trouble swallowing;
- lupus-like syndrome–joint pain or swelling with fever, swollen glands, muscle aches, chest pain, vomiting, unusual thoughts or behavior, and patchy skin color;
- signs of underactive thyroid–extreme tired feeling, dry skin, joint pain or stiffness, muscle pain or weakness, hoarse voice, feeling more sensitive to cold temperatures, weight gain; or
- severe skin reaction–fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Common side effects may include:
- nausea, vomiting, stomach pain;
- swollen glands;
- tingling or burning pain;
- headache, drowsiness, dizziness;
- swelling in your hands or feet;
- mild rash or itching;
- joint or muscle pain;
- 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.
Tell your doctor about all your current medicines and any you start or stop using, especially:
- digoxin (digitalis);
- heart or blood pressure medicine–atenolol, carvedilol, labetalol, metoprolol, propranolol, sotalol, and others; or
- a blood thinner–warfarin, Coumadin, Jantoven.
This list is not complete. Other drugs may interact with propylthiouracil, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
Use propylthiouracil regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.
Propylthiouracil can lower blood cells that help your body fight infections and help your blood to clot. This can make it easier for you to bleed from an injury or get sick from being around others who are ill.
Call your doctor if you have unusual bruising or bleeding, or signs of infection (fever, chills, sore throat).
While using propylthiouracil, you will need frequent blood tests to check your thyroid function.
Store at room temperature away from moisture and heat.
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Overdose symptoms may include nausea, vomiting, stomach pain, headache, joint pain, fever, chills, itching, swelling, loss of appetite, and feeling restless or drowsy.
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.