Propylthiouracil is used to treat
hyperthyroidism
(a condition that occurs when the thyroid gland produces too much thyroid hormone, speeding the body's metabolism, and causing certain symptoms) in adults and children 6 years of age or older.
What is the action of propylthiouracil?
Mechanism of Action
Propylthiouracil
inhibits the production of new thyroid hormone in the thyroid gland
. [2] It acts by inhibiting the enzyme thyroid peroxidase, which usually converts iodide to an iodine molecule and incorporates the iodine molecule into amino acid tyrosine.
What does propylthiouracil block?
PTU
inhibits iodine and peroxidase
from their normal interactions with thyroglobulin to form T4 and T3. This action decreases production of thyroid hormone. PTU also interferes with the conversion of T4 to T3, and, since T3 is more potent than T4, this also reduces the activity of thyroid hormones.
How do I know if propylthiouracil is working?
You will need
to have blood tests from time
to time to check that you are on the correct dose and that your liver is working well. This is because propylthiouracil can occasionally cause serious liver problems. Propylthiouracil should have some effect on your symptoms around three to four weeks after treatment starts.
What are the effects of propylthiouracil?
SIDE EFFECTS:
Stomach upset, nausea, vomiting, mild rash/itching, or headache may occur
. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
How does propylthiouracil PTU affect the body?
Propylthiouracil is an antithyroid medicine. It
works by making it harder for the body to use iodine to make thyroid hormone
. It does not block the effects of thyroid hormone that was made by the body before its use was begun.
Is PTU harmful?
The FDA has reported that
PTU can cause serious liver damage in
persons who take PTU including people who are pregnant. You and your healthcare team will decide what is best for your specific situation.
How long does propylthiouracil stay in your system?
Propylthiouracil is readily absorbed and is extensively metabolized. Approximately 35% of the drug is excreted in the urine, in intact and conjugated forms,
within 24 hours
.
Which is better PTU or methimazole?
Methimazole
— Methimazole is usually preferred over propylthiouracil because it reverses hyperthyroidism more quickly and has fewer side effects. Methimazole requires an average of six weeks to lower T4 levels to normal and is often given before radioactive iodine treatment. Methimazole can be taken once per day.
Should you take PTU with food?
Take this medication by mouth with or without food as directed by your doctor, usually
3 times a day
(every 8 hours). Dosage is based on your medical condition and response to treatment. Take this medication exactly as directed. Do not increase your dose or take it more often than prescribed.
Does propylthiouracil make you tired?
If you are taking propylthiouracil, call your doctor immediately if you develop any of the following symptoms: fever, loss of appetite, nausea, vomiting, tiredness, itching, dark urine, pale or light colored stools, yellowing of the skin or eyes, or pain in the upper right part of the stomach.
Can I take PTU at night?
To help keep the amount constant, do not miss any doses. Also, if you are taking more than one dose a day,
it is best to take the doses at evenly spaced times day and night
. For example, if you are to take 3 doses a day, the doses should be spaced about 8 hours apart.
How long can you take PTU?
Although propylthiouracil is used for the total treatment of hyperthyroidism, duration of treatment necessary to produce a prolonged remission varies from
6 months to several years
, with an average duration of one year.
What is the most serious potential adverse effect of propylthiouracil?
Agranulocytosis
.
Agranulocytosis
occurs in approximately 0.2% to 0.5% of patients and is a potentially life-threatening side effect of propylthiouracil therapy. Agranulocytosis typically occurs within the first 3 months of therapy.
Does propylthiouracil cause hair loss?
Anti-thyroid drugs (carbimazole and propylthiouracil) can, in rare cases,
cause diffuse hair loss
. It may be very difficult to tell whether the hair loss is due to the effects of the previous overactivity of the thyroid or the anti-thyroid drugs.
What happens when you stop taking PTU?
Effects of Skipping Thyroid Hormone Replacement
Blood pressure irregularities
.
Elevated cholesterol
, including treatment-resistant high cholesterol and increased risk of heart disease. Low body temperature; feeling perpetually cold. Fatigue, muscle weakness, or joint pain.
