Propylthiouracil

This information from Lexicomp® explains what you need to know about this medication, including what it’s used for, how to take it, its side effects, and when to call your healthcare provider.

Brand Names: Canada

Halycil; Propyl-Thyracil [DSC]

Warning

  • Liver problems have happened with this drug. Sometimes, this has been severe and has led to a liver transplant or death. If you have questions, talk with the doctor.
  • This drug is only for use when other treatments have not helped or cannot be used.

What is this drug used for?

  • It is used to treat an overactive thyroid gland.

What do I need to tell the doctor BEFORE my child takes this drug?

  • If your child is allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell the doctor about the allergy and what signs your child had.

This drug may interact with other drugs or health problems.

Tell the doctor and pharmacist about all of your child’s drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe to give this drug with all of your child’s other drugs and health problems. Do not start, stop, or change the dose of any drug your child takes without checking with the doctor.

What are some things I need to know or do while my child takes this drug?

  • Tell all of your child’s health care providers that your child is taking this drug. This includes your child’s doctors, nurses, pharmacists, and dentists.
  • Have your child avoid tasks or actions that call for alertness until you see how this drug affects your child. These are things like riding a bike, playing sports, or using items such as scissors, lawnmowers, electric scooters, toy cars, or motorized vehicles.
  • Have blood work checked as you have been told by the doctor. Talk with the doctor.
  • Your child may bleed more easily. Make sure your child is careful and avoids injury. Be sure your child has a soft toothbrush.
  • If the patient is a child, talk with the doctor. Most of the time, this drug is not for use in children.

If your child is pregnant or breast-feeding a baby:

  • This drug may cause harm to the unborn baby or loss of the unborn baby if your child takes it during pregnancy.
  • If your child is pregnant or gets pregnant while taking this drug, call the doctor right away.
  • Tell the doctor if your child is breast-feeding a baby. You will need to talk about any risks to the baby.

What are some side effects that I need to call my child’s doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your child’s doctor or get medical help right away if your child has any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of liver problems like dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
  • Signs of low thyroid levels like constipation; not able to handle cold; memory problems; mood changes; or a burning, numbness, or tingling feeling that is not normal.
  • Signs of lupus like a rash on the cheeks or other body parts, sunburn easy, muscle or joint pain, chest pain or shortness of breath, or swelling in the arms or legs.
  • Swollen gland.
  • Swelling.
  • Low blood cell counts have happened with this drug. If blood cell counts get very low, this can lead to bleeding problems, infections, or anemia. Call your child’s doctor right away if your child has signs of infection like fever, chills, or sore throat; any unexplained bruising or bleeding; or if your child feels very tired or weak.
  • Swelling of blood vessels has happened with this drug. This can include the small blood vessels in organs like the kidneys, skin, or lungs. Sometimes, this was severe and even deadly. Call the doctor right away if your child has any skin changes like red or purple color, rash, pain, or swelling; signs of kidney problems like change in how much urine is passed, pink or dark urine, or foamy urine; or signs of lung or breathing problems like shortness of breath or coughing up blood.
  • A severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause severe health problems that may not go away, and sometimes death. Get medical help right away if your child has signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in the mouth, throat, nose, or eyes.

What are some other side effects of this drug?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your child’s doctor or get medical help if any of these side effects or any other side effects bother your child or do not go away:

  • Headache.
  • Upset stomach or throwing up.
  • Stomach pain.
  • Muscle or joint pain.
  • Feeling dizzy or sleepy.
  • Hair loss.
  • Change in taste.

These are not all of the side effects that may occur. If you have questions about side effects, call your child’s doctor. Call your child’s doctor for medical advice about side effects.

You may report side effects to your national health agency.

How is this drug best given?

Give this drug as ordered by your child’s doctor. Read all information given to you. Follow all instructions closely.

  • Keep giving this drug to your child as you have been told by your child’s doctor or other health care provider, even if your child feels well.

What do I do if my child misses a dose?

  • Give a missed dose as soon as you think about it.
  • If it is close to the time for your child’s next dose, skip the missed dose and go back to your child’s normal time.
  • Do not give 2 doses at the same time or extra doses.

How do I store and/or throw out this drug?

  • Store at room temperature in a dry place. Do not store in a bathroom.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

General drug facts

  • If your child’s symptoms or health problems do not get better or if they become worse, call your child’s doctor.
  • Do not share your child’s drug with others and do not give anyone else’s drug to your child.
  • Some drugs may have another patient information leaflet. If you have any questions about this drug, please talk with your child’s doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Consumer Information Use and Disclaimer

This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider’s examination and assessment of a patient’s specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms.

Last Reviewed Date

2020-12-11

Copyright

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Last Updated

Monday, December 12, 2022