Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Propylthiouracil 100mg Tablets
⚠ This medicine appears to have been discontinued
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Propylthiouracil may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
What it is and what it is used for
ice) The active ingredient in Propylthiouracil Tablets is propylthiouracil. Propylthiouracil Tablets are used in the treatment of hyperthyroidism. Hyperthyroidism is where an overactive thyroid gland produces too much thyroid hormone. They are also used to treat Graves' disease, thyrotoxicosis and thyrotoxic crisis (when levels of thyroid hormone are dangerously high). Propylthiouracil Tablets may also be given to lower very high levels of thyroid hormone before surgery or radioactive iodine treatment. Children may be given Propylthiouracil Tablets to delay the need for surgery (or other treatment to remove part of an overactive thyroid gland).
What you need to know before you take it
e Propylthiouracil Tablets
Do not take Propylthiouracil Tablets if you:
- are allergic to propylthiouracil or any of the other ingredients of this medicine (listed in section 6.) Warnings and precautions Talk to your doctor or pharmacist before taking Propylthiouracil Tablets if you: ¢ have ever had an adverse reaction to propylthiouracil or to any of the other ingredients of this medicine (listed in section 6.);
- are pregnant, may become pregnant or are breastfeeding;
¢ have ever had any problems with your liver or kidneys;
- are older than 40 years of age. Check with your doctor if any of the following applies to you: Some cases of severe liver reactions, including cases with fatal outcome or requiring liver transplant, have been reported in both children and adults treated with propylthiouracil. You should inform your doctor immediately if you develop symptoms of liver disease, such as nausea, feeling sick, diarrhoea, yellow discolouration of the skin or eyes, dark urine, pale stools, bleeding easily, itching or chills. Other medicines and Propylthiouracil Tablets Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. Some medicines can interfere with your treatment. Tell your doctor if you are taking any of the following: ¢ Any mineral supplements in your diet which may contain iodine.
- Medicines which will reduce the number of white blood cells in your body and hence lower your resistance to infection. If you are not sure, you should ask your doctor or pharmacist who will be able to give you this information. ¢ Medicines containing theophylline, aminophylline or digoxin. ¢ Other medicines including ones that you have bought for yourself without a prescription. Pregnancy and breast-feeding The potential of Propylthiouracil Tablets to cause harm to an unborn baby is uncertain. If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, tell your doctor or pharmacist for advice before taking this medicine. You may need treatment with Propylthiouracil Tablets during pregnancy if the potential benefit outweighs the potential risk to you and your unborn baby. Driving and using machines Propylthiouracil has no documented effects on the ability to drive or use machines. However, if you feel drowsy or confused, you should not drive or operate machines. Propylthiouracil Tablets contain lactose If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product. Important information about Propylthiouracil Tablets This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially 'sodium-free'. If you see another doctor or visit a hospital, remember to tell them what medicines you are already taking.
How to take it
Propylthiouracil Tablets Always take this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure. The dose will be on the pharmacist's label. Check the label carefully. It should tell you how many tablets to take and how often. Your doctor may want you to have regular blood tests or other tests to check your condition and to make sure that you are taking the right dose. Swallow the tablets whole with water. The following doses are intended as a guide: Adults: For management of hyperthyroidism and prior to surgery: the starting dose is between 300mg and 600mg a day, taken as a single dose or in divided doses. This may be gradually reduced to between 50mg and 150mg daily as your condition improves. In preparation for radioactive iodine therapy: The dose is as above and should be taken for several weeks prior to radioactive iodine therapy. Treatment should be stopped 2 to 4 days before iodine treatment. For thyrotoxic crisis: The dose is 200mg every 4 to 6 hours for the first 24 hours. This is then reduced as the condition improves. Elderly patients will be given the adult dose mentioned above. Patients with liver or kidney problems may be given a lower dose. Children: Aged 6 to 10 years: The starting dose is 50mg to 150mg a day. Aged over 10 years: The starting dose is 150mg to 300mg a day. Neonates (babies less than 4 weeks old): The dose will be worked out depending on the baby's weight. The usual daily dose is 5mg to 10mg for each kilogram of body weight. If you forget to take Propylthiouracil Tablets If you forget to take a dose at the right time, take it as soon as you remember. Do not take two doses together. If it is almost time to take the next dose, wait until then and then carry on as before.
If you take more Propylthiouracil Tablets than you should It is important not to take too many tablets. Contact your nearest
Possible side effects
you can help provide more information on the safety of this medicine.
MPL18229
- P1.1
Item code
How to store it
Propylthiouracil Tablets
hospital casualty department or a doctor for advice if you have swallowed too many tablets or if you think a child has swallowed any. Take this leaflet, and any tablets that you still have to show the doctor.
This medicinal product does not require any special storage conditions.
If you have any further questions on the use of this medicine, ask your doctor or pharmacist.
Do not take this medicine after the expiry date which is stated on the carton and label. The expiry date refers to the last day of that
4. Possible side effects
Keep this medicine out of the sight and reach of children.
month.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help to protect the environment.
Tell your doctor immediately if you get:
Contents of the pack and other information
¢ A fever, sore throat, rashes or ulcers in your mouth and throat,
as this could be a sign that you are not making any white blood cells to fight off infection. If this happens your treatment should be stopped. However this is a rare side effect and occurs most commonly within the first two months of treatment and in
What Propylthiouracil Tablets contain Each tablet contains either 50 mg or 100 mg of propylthiouracil as the active ingredient.
patients over the age of 40 who are taking larger doses. ¢ Fever, joint swelling and pain, muscle aches, blood in urine, shortness of breath, rash.
The other excipients in each tablet are starch pregelatinised, lactose monohydrate, sodium starch glycolate (Type-A), povidone K-30 and magnesium stearate.
Propylthiouracil may cause the increase of a particular type of antibody "ANCA" (anti-neutrophil cytoplasmic antibodies) and inflammation of the walls of blood vessels which can be serious if not treated. This can occur even if you have been taking propylthiouracil for many years.
What Propylthiouracil Tablets look like and contents of the pack Propylthiouracil 50 mg Tablets are white to off-white coloured, round shaped, biconvex, uncoated tablets debossed with P1 on one side and plain on other side.
You should tell your doctor if you suffer from any of the following for more than a few days:
Propylthiouracil 100 mg Tablets are white to off-white coloured, round shaped, biconvex, uncoated tablets debossed with P2 on one side and plain on other side.
¢ Rash;
ltching; Hair loss; Skin colourations; Swelling (for example in the legs and feet); Being and feeling sick; Stomach upset; Loss of taste; Muscle or joint pain;
¢ Pins and needles and headache. Frequency unknown: Liver failure, liver inflammation. Other rare side effects are: ¢ Anaemia, fever, weak and tender muscles, lupus-likesyndrome (seen as a red, scaly rash on the nose and cheeks and/or stiffness in the joints and malaise); ¢ Liver damage or inflammation, which can include hepatitis,
jaundice (yellow skin and whites of the eyes), confusion, coma and death; ¢ Kidney inflammation (blood in the urine), bruises and blood spots due to inflammation of the small blood vessels in the skin, breathlessness and cough; ¢ Slow blood clotting, bleeding and bruising more easily than usual. If you feel unwell in any other way, tell your doctor as soon as you can. Your body may make less white blood cells than normal which may make you more prone to picking up infections.
The tablets are packaged in Alu-Alu blister in packs of 7, 14, 21, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120 or 500 tablets. Not all pack sizes may be marketed. Marketing Authorisation Holder Morningside Healthcare Ltd. Unit C, Harcourt Way Leicester, LE19 1WP UK Manufacturer
Morningside Pharmaceuticals Ltd. 5 Pavilion Way, Loughborough Leicestershire, LE11 UK
5GW
Morningside Pharmaceuticals Ltd. & Aspire Pharma Ltd. Second Floor, Boss Court, 7 Barton Close, Grove Park, Leicester, LE19 1SJ, United Kingdom Aspire Pharma Ltd. Unit 4, Rotherbrook Court, Bedford Road, Petersfield, GU32 3QG, United Kingdom. This leaflet was last revised in May 2025.
Levels will go back to normal when you stop taking your treatment. Reporting of side effects If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via Yellow Card Scheme on the MHRA website www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting
Frequently asked questions about Propylthiouracil 100mg Tablets
How do I take Propylthiouracil 100mg Tablets?
Propylthiouracil 100mg Tablets comes as tablet containing 100mg. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.
What is the active substance in Propylthiouracil 100mg Tablets?
The active substance in Propylthiouracil 100mg Tablets is propylthiouracil.
Where does this information come from?
This leaflet reproduces the patient information leaflet approved for Propylthiouracil 100mg Tablets, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Can I get Propylthiouracil 100mg Tablets without a prescription?
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
About this leaflet
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
- Source: electronic medicines compendium (emc), Datapharm
- Active substance: propylthiouracil
- Official document: view the original leaflet on emc →
⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+
4.1. Therapeutic indications
1. Management of hyperthyroidism, including the treatment of Graves' disease and thyrotoxicosis.
2. Amelioration of hyperthyroidism in preparation for surgical treatment.
3. An adjunct to radioactive iodine therapy.
4. In juvenile hyperthyroidism to delay ablative therapy.
5. To manage thyrotoxic crisis.
4.2. Posology and method of administration
Posology
Adults:
Management of Hyperthyroidism
The initial dose of propylthiouracil is between 300mg and 600mg given as a single daily dose. This dose should be maintained until the patient becomes euthyroid. The dose should then be reduced gradually to a maintenance dose of between 50mg and 150mg, taken as a single daily dose.
Daily doses can be divided if preferred.
Preparation for Surgery
As for management of hyperthyroidism, until the patient becomes euthyroid.
Adjunct to Radioactive Iodine Therapy
As for management of hyperthyroidism, for several weeks prior to radio-iodine treatment. Withdraw propylthiouracil 2 to 4 days before irradiation. The dosage of radio-iodine may need to be adjusted because propylthiouracil may have a radioprotective effect.
Management of Thyrotoxic Crisis
200mg every 4 to 6 hours for the first 24 hours, decrease the dose as the crisis subsides.
Elderly
The adult dose should apply, but caution is advised in the presence of renal or hepatic impairment, where a dosage reduction may be justified.
Children:
Juvenile Hyperthyroidism
Children aged 6 - 10 years:
Initial dose of 50-150mg daily
Children over 10 years:
Initial dose of 150-300mg (or 150mg/m2) daily
Maintenance dose is determined by the patient's response.
Treatment of Hyperthyroidism in Neonates:
5-10mg/kg daily.
No other specific children's doses are known.
Method of administration
Propylthiouracil is administered by the oral route.
4.3. Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
4.4. Special warnings and precautions for use
Patients should be made aware that the development of certain adverse effects (fever, mouth ulcers, rashes, sore throat) may be an indication of agranulocytosis, a serious reaction to the drug, and they should contact their doctor immediately as treatment should be stopped. A full blood count should be performed if there is clinical evidence of infection. Likewise propylthiouracil should be used with extreme caution in patients receiving other drugs known to cause agranulocytosis. Use propylthiouracil with caution in patients more than 40 years old.
Decrease the dose of propylthiouracil in renal failure. If the glomerular filtration rate is 10-50ml/min, decrease dose by 25%. If the GFR is <10ml/min decrease dose by 50%.
Propylthiouracil may cause hypothrombinaemia and bleeding so prothrombin time should be monitored during therapy, especially prior to surgery.
Discontinue propylthiouracil if clinically important evidence of abnormal liver function occurs.
Prolonged therapy and/or excessive doses of propylthiouracil may cause hypothyroidism so thyroid function should be monitored regularly.
Another serious side effect is systemic vasculitis which can occur anytime and up to several years after initiation of treatment with propylthiouracil. Risk of systemic vasculitis may increase with prolonged use. Renal involvement is most common but skin, lung and musculoskeletal systems may also be involved. In severe cases death can occur. Propylthiouracil should be discontinued promptly and treatment initiated as required.
Some cases of severe hepatic reactions, both in adults and children, including fatal cases and cases requiring a liver transplant have been reported with propylthiouracil. Time to onset has varied but in a majority of cases the liver reaction occurred within 6 months. If significant hepatic enzyme abnormalities develop during treatment with propylthiouracil the drug should be discontinued immediately (see section 4.8).
Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Important information about ingredients:
This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially 'sodium-free'.
4.5. Interaction with other medicinal products and other forms of interaction
The response of the thyroid gland to propylthiouracil may be impaired by a concurrent high iodine intake.
Drug induced changes in thyroid status may affect the dosage requirements for theophylline and digitalis. The doses of digitalis and theophylline may need to be reduced as thyroid function returns to normal.
4.6. Fertility, pregnancy and lactation
Women of childbearing potential
Women of childbearing potential should be informed about the potential risks of propylthiouracil use during pregnancy.
Pregnancy
Hyperthyroidism in pregnant women should be adequately treated to prevent serious maternal and foetal complications.
Propylthiouracil is able to cross the human placenta.
Animal studies are insufficient with respect to reproductive toxicity. Epidemiological studies provide conflicting results regarding the risk of congenital malformations.
Individual benefit/risk assessment is necessary before treatment with propylthiouracil during pregnancy. Propylthiouracil should be administered during pregnancy at the lowest effective dose without additional administration of thyroid hormones. If propylthiouracil is used during pregnancy, close maternal, foetal and neonatal monitoring is recommended.
Breast-feeding
Propylthiouracil is present in breast milk in small amounts and neonatal development should be closely monitored in any nursing mother treated with this drug.
Fertility
No studies on the effect on human fertility have been conducted for Propylthiouracil.
4.7. Effects on ability to drive and use machines
Propylthiouracil has no documented effects on the ability to drive or use machines.
4.8. Undesirable effects
Minor adverse effects of propylthiouracil include: rash, urticaria, pruritus, abnormal hair loss, skin pigmentation, oedema, nausea, vomiting, epigastric distress, loss of taste, arthralgia, myalgia, paresthesia and headache.
Leucopenia is a common adverse effect, but it is usually mild and reversible.
Agranulocytosis is the most serious adverse effect of propylthiouracil, but the incidence is very low. It tends to occur within the first two months of therapy and patients over the age of 40 years and receiving larger doses are at greater risk.
Frequency unknown: Hepatitis, Hepatic Failure
Other severe, but infrequent adverse events include: aplastic anaemia; drug fever; lupus-like syndrome; severe hepatic reactions (including encephalopathy, fulminant hepatic necrosis and death); periarteritis; hypoprothrombinaemia; thrombocytopenia and bleeding.
Nephritis, interstitial pneumonitis, cutaneous and systemic vasculitis and polymyositis have also been reported. Hypersensitivity reactions may be associated with the development of anti-neutrophil cytoplasmic antibodies (ANCA).
Propylthiouracil-induced hepatoxicity is rare and usually manifests as hepatocellular hepatitis with or without jaundice. Cholestatic jaundice has also occurred. Adverse liver effects are generally reversible on cessation of propylthiouracil.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme on the MHRA website www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
4.9. Overdose
Symptoms of propylthiouracil overdose include: nausea, vomiting, epigastric distress, headache, fever, arthralgia, pruritus, oedema and pancytopenia, exfoliative dermatitis and hepatitis have occurred. Agranulocytosis is the most severe potential adverse effect due to acute propylthiouracil toxicity.
The treatment of propylthiouracil overdose should aim to minimise the amount of drug absorbed into the circulation. Following acute toxicity the stomach should be emptied by gastric lavage or emesis. Activated charcoal may also be employed. General symptomatic and supportive measures should then be instituted. A full blood analysis should be considered because of the slight risk of haematological complications and appropriate therapy given if bone marrow depression develops.
There is no specific antidote for propylthiouracil.
🇵🇱 Known in Poland as
Medicines sold in Poland with the same active substance: W Polsce znany jako
- ThyrosanPropylthiouracilum · taken by mouth
- Propycil 50 mgPropylthiouracilum · taken by mouth
Same active substance. The strength, the form and whether you need a prescription can differ. Always ask a pharmacist before you switch. Polish medicines in the UK →
💬 Ask about this leaflet
Ask anything about Propylthiouracil 100mg Tablets. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.