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propylthiouracil (PTU)

Propyl-Thyracil (CA)

Pharmacologic class: Thioamide derivative

Therapeutic class: Antithyroid agent

Pregnancy risk category D

FDA Box Warning

• Drug has caused severe liver injury and acute liver failure, in some cases fatal. These reports of hepatic reactions include cases requiring liver transplant.

• Reserve drug for patients intolerant of methimazole and in whom radioactive iodine therapy or surgery isn't appropriate for management of hyper-thyroidism.

• Because of risk of fetal abnormalities associated with methimazole, propylthiouracil may be treatment of choice when an antithyroid drug is indicated during or just before first trimester.


Directly interferes with thyroid synthesis by preventing iodine from combining with thyroglobulin, leading to decreased thyroid hormone levels


Tablets: 50 mg

Indications and dosages


Adults: Initially, 300 to 450 mg P.O. daily in equally divided doses q 8 hours; for maintenance, 100 to 150 mg P.O. daily.

Thyrotoxic crisis

Adults: 200 mg P.O. q 4 to 6 hours during first 24 hours, then a maintenance dosage of 100 to 150 mg P.O. daily


• Hypersensitivity to drug


Use cautiously in:

• decreased bone marrow reserve

• pregnancy and breastfeeding patients

• children.


• Give with meals to reduce GI upset.

• Be aware that drug shouldn't be used in children unless patient is allergic to or intolerant of methimazole, and there are no other treatment options available.

Adverse reactions

CNS: drowsiness, headache, vertigo, neuritis, paresthesia

GI: nausea, vomiting, diarrhea, epigastric distress

Hematologic: agranulocytosis, leukopenia, thrombocytopenia

Hepatic: jaundice, hepatic necrosis, liver failure

Metabolic: hypothyroidism

Musculoskeletal: joint pain, myalgia

Skin: rash, urticaria, pruritus, skin discoloration, alopecia, cutaneous vasculitis

Other: taste loss, fever, lymphadenopathy, parotitis, edema


Drug-drug. Anticoagulants: potentiation of anticoagulant effect

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, lactate dehydrogenase: increased levels

Granulocytes, platelets: decreased levels Prothrombin time: prolonged

Patient monitoring

• Monitor CBC and liver and thyroid function tests.

• Assess for signs and symptoms of hypothyroidism (cold intolerance, nonpitting edema, fatigue, weight gain, and depression).

Monitor for severe rash, fever, jaundice, or enlarged cervical lymph nodes. If present, stop therapy and notify prescriber.

Patient teaching

• Instruct patient to take with meals to reduce GI upset.

• Teach patient to recognize and report signs and symptoms of hypothyroidism and jaundice.

• Advise patient to discuss iodine intake (as in iodized salt and shellfish) with prescriber.

• Tell patient to avoid over-the-counter cold remedies that contain iodine.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Advise female patient of childbearing age to discuss pregnancy or breastfeeding with prescriber before taking.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


Abbreviation for propylthiouracil.
Farlex Partner Medical Dictionary © Farlex 2012


The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
References in periodicals archive ?
Nevertheless, PTU treatment could not decrease either the T4-induced increase in HW or the HW/BW ratio compared to the T4-treated mice and they still are significantly higher than those of the basal group (P < 0.001 and P < 0.001, resp.) (Table 2).
PTU is administered around the clock (usually every 8 hours).
Surprisingly, the 5-day PTU treatment with 5 mg/100 g BW led to an increase of Mb mRNA content in skeletal muscles (Figure 2E), followed by a decrease to control values when extending the treatment to day P15 (Figure 2F).
A tireoidectomia deve ser considerada em caso de alergia, contraindicacoes as drogas antitireoidianas, em pacientes que requerem altas doses das medicacoes (MMZ 30 mg/dia e PTU 450 mg/dia) ou quando nao ha resposta ao tratamento medicamentoso.
Wadw et al have reported 25% of patients were positive for MPO-ANCA in PTU group whereas in methimazole group 3.4% were positive (10).
Among 51 patients treated with PTU, 26 patients started treatment during the first trimester, 22 patients started during the second trimester, and 3 patients started during the third trimester.
Regarding the other groups, PTU has reduced the plasma fibrinogen values (p = 0.013) of approximately 30% at the 24th h and of 20% at the 48th h, while time (p = 0.946) and interaction (p = 0.508) differences were not registered for this variable (Figure 1).
Although accretion of GDD and PTU for each phenophase is somewhat constant but different wheat varieties can modify it noticeably (Phadnawis and Saini, 1992).
He was addressing a function after opening of the project of Punjab Technology University (PTU) at Arfa Karim Software Technology Park here.
The CM, while addressing a function at the Arfa Karim IT Centre, said the first campus of the PTU had been set up on the sixth floor of Arfa Karim Software Technology Park where classes would start from September this year, says a government handout.
The Punjab government will provide free of cost land for Punjab Technology University (PTU), which will be managed by an autonomous board so that it should have the highest standard of computer education.
Also recommended is a more cautious approach to the use of propylthiouracil (PTU).