pharmacopeia
GET
/api/v1/drug/propylthiouracil

Boxed warning

Severe liver injury and acute liver failure, in some cases fatal, have been reported in patients treated with propylthiouracil. These reports of hepatic reactions include cases requiring liver transplantation in adult and pediatric patients. Propylthiouracil should be reserved for patients who cannot tolerate methimazole and in whom radioactive iodine therapy or surgery are not appropriate treatments for the management of hyperthyroidism. Propylthiouracil may be the treatment of choice when an antithyroid drug is indicated during or just prior to the first trimester of pregnancy (see Warnings and Precautions ).

2D structure
6-propyl-2-sulfanylidene-1H-pyrimidin-4-one
SMILES CCCC1=CC(=O)NC(=S)N1
InChIKey KNAHARQHSZJURB-UHFFFAOYSA-N

Mechanism of action

Sourced from openFDA

Mechanism-of-action classes: Organic Anion Transporter Interactions; Protein Synthesis Inhibitors; Thyroid Hormone Synthesis Inhibitors; Uncouplers.

Protein SynthesisThyroid Hormone Synthesis

Indications

Sourced from openFDA
  • Propylthiouracil is indicated: in patients with Graves’ disease with hyperthyroidism or toxic multinodular goiter who are intolerant of methimazole and for whom surgery or radioactive iodine therapy is not an appropriate treatment option to ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy in patients who are intolerant of methimazole.ICD-10: E05.90

Contraindications

Sourced from openFDA
  • Propylthiouracil is contraindicated in patients who have demonstrated hypersensitivity to the drug or any of the other product components.contraindicated

Dosage & administration

Sourced from openFDA

Propylthiouracil is administered orally. The total daily dosage is usually given in 3 equal doses at approximately 8-hour intervals. Adults The initial dose is 300 mg daily. In patients with severe hyperthyroidism, very large goiters, or both, the initial dose may be increased to 400 mg daily; an occasional patient will require 600 to 900 mg daily initially. The usual maintenance dose is 100 to 150 mg daily. Pediatric Patients Propylthiouracil is generally not recommended for use in the pediatric patient population except in rare instances in which other alternative therapies are not appropriate options. Studies evaluating appropriate dosing regimen have not been conducted in the pediatric population although general practice would suggest initiation of therapy in patients 6 years or older at a dosage of 50 mg daily with careful upward titration based on clinical response and evaluation of TSH and free T4 levels. Although cases of severe liver injury have been reported with doses as low as 50 mg/day, most cases were associated with doses of 300 mg/day and higher. Geriatric Patients Clinical studies of propylthiouracil did not include sufficient numbers of subjects aged 65 or over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Warnings & precautions

Sourced from openFDA

Liver Toxicity Liver injury resulting in liver failure, liver transplantation, or death, has been reported with propylthiouracil therapy in adult and pediatric patients. No cases of liver failure have been reported with the use of methimazole in pediatric patients. For this reason, propylthiouracil is not recommended for pediatric patients except when methimazole is not well-tolerated and surgery or radioactive iodine therapy are not appropriate therapies. Biochemical monitoring of liver function (bilirubin, alkaline phosphatase) and hepatocellular integrity (ALT, AST) is not expected to attenuate the risk of severe liver injury due to its rapid and unpredictable onset. Patients should be informed of the risk of liver failure. Patients should be instructed to report any symptoms of hepatic dysfunction (anorexia, pruritus, right upper quadrant pain, etc.), particularly in the first six months of therapy. When these symptoms occur, propylthiouracil should be discontinued immediately and liver function tests and ALT and AST levels obtained. Use in Pregnancy There are cases of liver injury, including liver failure and death, in women treated with propylthiouracil during pregnancy. Two reports of in utero exposure with liver failure and death of a newborn have been reported. If propylthiouracil is used during pregnancy, or if the patient becomes pregnant while taking propylthiouracil, the patient should be warned of the rare potential hazard to the mother and fetus of liver damage.

Adverse reactions

Sourced from openFDA

The following adverse reactions have been reported with the use of propylthiouracil. Because these events generally come from voluntary reporting from a population of uncertain size, it is not possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Severe adverse reactions include liver injury presenting as hepatitis, liver failure necessitating liver transplantation or resulting in death (see WARNINGS ). Inhibition of myelopoiesis (agranulocytosis, granulopenia, aplastic anemia, and thrombocytopenia), drug fever, a lupus-like syndrome (including splenomegaly and vasculitis), periarteritis, hypoprothrombinemia, and bleeding have been reported. Nephritis, glomerulonephritis, interstitial pneumonitis, exfoliative dermatitis, and erythema nodosum have also been reported. There are reports of a vasculitis associated with the presence of anti-neutrophilic cytoplasmic antibodies (ANCA), resulting in severe complications and death (see WARNINGS ). There have been rare reports of serious hypersensitivity reactions (e.g., Stevens Johnson syndrome and toxic epidermal necrolysis) in patients treated with propylthiouracil. Other adverse reactions include skin rash, uticaria, nausea, vomiting, epigastric distress, arthralgia, paresthesias, loss of taste, taste perversion, abnormal loss of hair, myalgia, headache, pruritus, drowsiness, neuritis, edema, vertigo, skin pigmentation, jaundice, sialadenopathy, and lymphadenopathy.

Overdosage

Sourced from openFDA

Signs and Symptoms Nausea, vomiting, epigastric distress, headache, fever, arthralgia, pruritus, edema, and pancytopenia. Agranulocytosis is the most serious effect. Rarely, exfoliative dermatitis, hepatitis, neuropathies or CNS stimulation or depression may occur. No information is available on the following: LD 50 ; concentration of propylthiouracil in biologic fluids associated with toxicity and/or death; the amount of drug in a single dose usually associated with symptoms of overdosage; or the amount of propylthiouracil in a single dose likely to be life-threatening. Treatment To obtain up-to-date information about the treatment of overdose, a good resource is the certified Regional Poison Control Center. In managing overdosage, consider the possibility of multiple drug overdoses, interaction among drugs, and unusual drug kinetics in the patient. In the event of an overdose, appropriate supportive treatment should be initiated as dictated by the patient’s medical status.

Approval history

Sourced from openFDA
  • Jul 28, 1947NDANDA006188Ph Health
  • Jul 24, 1970ANDAANDA080016Chartwell Molecular
  • Jul 23, 1971ANDAANDA080154Quagen
  • Jan 9, 1973ANDAANDA080172Actavis Elizabeth
  • May 10, 2023ANDAANDA208867Macleods Pharms Ltd

FAERS reports

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Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
2,019 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Drug Ineffective1939.6%
  2. 2Off Label Use1507.4%
  3. 3Hyperthyroidism1356.7%
  4. 4Foetal Exposure During Pregnancy1165.7%
  5. 5Nausea874.3%
  6. 6Exposure During Pregnancy854.2%
  7. 7Anti-neutrophil Cytoplasmic Antibody Positive Vasculitis844.2%
  8. 8Maternal Exposure During Pregnancy723.6%
  9. 9Hypotension673.3%
  10. 10Agranulocytosis592.9%
  11. 11Fatigue582.9%
  12. 12Pyrexia582.9%
  13. 13Vomiting572.8%
  14. 14Product Use In Unapproved Indication562.8%
  15. 15Cardiac Arrest552.7%

Literature

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Recent PubMed references pinned to Propylthiouracil as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 10 most recently updated of 16 ClinicalTrials.gov registrations naming Propylthiouracil as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Pharmacogenomics

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CPIC-curated drug–gene pairs for Propylthiouracil. Levels describe the strength of curated evidence and guideline status — never a recommendation to test or to adjust therapy.

  • HLA-BCPIC C (provisional)ClinPGx 3

Structural analogs

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Ranked by 2D fingerprint (Tanimoto) similarity over PubChem structures. Structural proximity only — not a claim of therapeutic equivalence.

Frequently asked questions

How does Propylthiouracil work?
Mechanism-of-action classes: Organic Anion Transporter Interactions; Protein Synthesis Inhibitors; Thyroid Hormone Synthesis Inhibitors; Uncouplers.
What is Propylthiouracil used for?
According to FDA labeling, Propylthiouracil carries indications including: Propylthiouracil is indicated: in patients with Graves’ disease with hyperthyroidism or toxic multinodular goiter who are intolerant of methimazole and for whom surgery or radioactive iodine therapy is not an appropriate treatment option to ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy in patients who are intolerant of methimazole.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Propylthiouracil?
Propylthiouracil is classified as Thiouracils, Thyroid Hormone Synthesis Inhibitor, Organic Anion Transporter Interactions, Protein Synthesis Inhibitors, Thyroid Hormone Synthesis Inhibitors, Uncouplers, Decreased Iodine Organification, Decreased Protein Modification, Decreased Protein Synthesis, Decreased Thyroid Hormone Iodination.
What are the contraindications for Propylthiouracil?
Propylthiouracil labeling lists contraindications including: Propylthiouracil is contraindicated in patients who have demonstrated hypersensitivity to the drug or any of the other product components.. Always consult the full prescribing information and a clinician.
Note. Data for propylthiouracil is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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