- March 15, 2022
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Brand Name :
PTU
Synonyms :
propylthiouracil
Class :
Antithyroid agents
Dosage forms & Strengths
Tablet
50mg
hyperthyroidism and Thyrotoxicosis
300-450 mg orally divided every 8 hours, depending on the severity of the condition
(A dose of 600-900 mg/day maybe required)
Maintenance dose- 100-150 mg orally divided every 8 hours
Thyrotoxic Crisis
(Off-label)
Initially 200-300 mg orally every 4-6 hours on 1st day
Reduce the dose gradually
Maintenance dose- 100-150 mg/day divided 2-3 times daily
Initially 50-150 mg orally every 8 hours
Maintenance dose- 50 mg orally 2-3 times daily, for 12-18 months
Taper the dose until euthyroid is attained
Dosage forms & Strengths:
Tablet:
50 mg
hyperthyroidism and Thyrotoxicosis
Indicated in children for hyperthyroidism only
For neonates, less than 28 days old: 5-10 mg/kg orally divided 3 times daily
For <6 years: 5-7 mg/kg orally divided 3 times daily
For 6-10 years: 50-150 mg orally divided 3 times daily
For >10 years: 150-300 mg orally divided daily
Maintenance dose: Usually one to two third of the intial dose 2-3 times daily based on the response
Refer to the adult dosing
They may diminish the serum concentration when combined with bile acid sequestrants
they both increase the effect of each other when used simultaneously
they both increase the effect of each other when used simultaneously
they both increase the effect of each other when used simultaneously
they both increase the effect of each other when used simultaneously
they both increase the toxicity of each other when used simultaneously
they both increase the toxicity of each other when used simultaneously
they both increase the effect of each other when used simultaneously
may increase the arrhythmogenic affect
may diminish the serum concentration when combined with thyroid products
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
estrogens esterified/methyltestosterone
may decrease the therapeutic effect of estrogen derivatives
they increase the effect of each other by pharmacodynamic synergism
they increase the effect of each other by pharmacodynamic synergism
they increase the effect of each other by pharmacodynamic synergism
Actions and Spectrum:
Actions:
Spectrum:
Frequency not defined
Agranulocytosis
Aplastic anemia
Hepatitis
Polyarthritis
Drowsiness
Vertigo
Alopecia
Erythema nodosum
Skin ulcers
Goiter
Weight gain
Constipation
Loss of taste
Granulopenia
Leukopenia
Thrombocytopenia
Black Box Warning:
Severe liver injury and acute liver failure are rare but serious side effects of propylthiouracil, and patients taking this medication should be closely monitored for symptoms and signs of liver injury. The FDA recommends that healthcare providers measure liver function tests prior to initiating treatment with propylthiouracil and periodically thereafter, especially during the first six months of therapy.
propylthiouracil should be reserved for those patients who cannot tolerate other treatments, such as methimazole, radioactive iodine, or surgery, due to the potential risk of liver injury. In pregnant women with hyperthyroidism, propylthiouracil may be the treatment of choice during the first trimester of pregnancy due to the strong association of methimazole with congenital malformations during this period. However, in later stages of pregnancy, methimazole is generally preferred due to a lower risk of liver injury in the mother.
Contraindication/Caution:
Contraindications:
Precautions:
Pregnancy consideration:
Category D
Breastfeeding warnings:
Propylthiouracil is distributed in breastmilk and hence contraindicated during breastfeeding
Pregnancy category:
Pharmacology:
propylthiouracil (PTU) is an antithyroid medication used in the treatment of hyperthyroidism, which is the overactivity of the thyroid gland that leads to excessive thyroid hormone production. Here are some key points about the pharmacology of PTU:
Pharmacodynamics:
The pharmacodynamics of PTU involve inhibition of both thyroid hormone synthesis and peripheral conversion, leading to a reduction in circulating levels of T4 and T3 and improvement in symptoms of hyperthyroidism. The slow onset and prolonged duration of action of the drug must be considered when managing patients with hyperthyroidism.
Pharmacokinetics:
Absorption
The 75% of drug is absorbed
Duration of action is 12-24 hours
The half-life of elimination is 1-2 hours
Distribution
The volume of distribution is 0.4 L/kg
The bound protein is 80-85%
Peak plasma concentration is achieved in 1-2 hours
The peak plasma concentration is 6-9 mcg/mL
Metabolism
The drug is metabolised in the liver, to glucuronide conjugates, sulfur metabolites, inorganic sulfates
Elimination and Excretion
The rate of total body clearance is 7 L/hr
The drug is excreted 35% in urine
Administration:
propylthiouracil (PTU) is an anti-thyroid medication used to treat hyperthyroidism, a condition where the thyroid gland produces too much thyroid hormone. PTU works by inhibiting the production of thyroid hormone by blocking the activity of an enzyme called thyroid peroxidase.
PTU is usually taken orally in tablet form, and the dose and duration of treatment will depend on the individual patient’s condition and response to the medication. It is important to take the medication exactly as prescribed by the healthcare provider and not to stop taking it abruptly without medical advice, as this can cause a rebound increase in thyroid hormone levels.
PTU can have several potential side effects, including nausea, vomiting, loss of appetite, headache, dizziness, rash, and joint pain. Rare but serious side effects can also occur, such as liver toxicity and a decrease in white blood cell count. Patients should be monitored closely for any signs of these side effects and advised to seek medical attention immediately if they occur.
In addition, PTU should not be used during pregnancy unless the benefits outweigh the risks, as it can cross the placenta and potentially harm the developing fetus. It is also important to inform the healthcare provider of any other medications or supplements being taken, as they may interact with PTU and affect its effectiveness or increase the risk of side effects.
Patient information leaflet
Generic Name: propylthiouracil
Pronounced: PRO-pil-THYE-oh-URE-a-sil
Why do we use propylthiouracil?
propylthiouracil (PTU) is used to treat hyperthyroidism, a condition where the thyroid gland produces too much thyroid hormone. Hyperthyroidism can be caused by various conditions, including Graves’ disease, toxic multinodular goiter, and toxic adenoma.
PTU works by inhibiting the production of thyroid hormone by blocking the activity of an enzyme called thyroid peroxidase. This enzyme is required for the synthesis of thyroid hormone, and by inhibiting its activity, PTU reduces the amount of thyroid hormone produced by the thyroid gland.
PTU is often used as a first-line treatment for hyperthyroidism, particularly in patients who cannot tolerate or have contraindications to other anti-thyroid medications like methimazole. PTU may also be used in combination with other medications or radioactive iodine therapy to achieve better control of hyperthyroidism.
In addition to treating hyperthyroidism, PTU may also be used to prepare patients for thyroid surgery by reducing the size and activity of the thyroid gland before the procedure.