Propylthiouracil may provide benefits to those with a thyroid disease, but patients should note some common side effects prior to taking the drug.
This anti-thyroid medication, also known as PTU, is designed to help those with an overactive thyroid gland that produces too many
thyroid hormones, according to Rx List. This condition is also known as hyperthyroidism.
PTU prevents the thyroid gland from producing
T3 and T4 hormones, Endocrine Web reported. In doing so, it can help treat the symptoms of hyperthyroidism, including Graves’ disease and the lump on a patient’s neck due to swelling of the thyroid gland, which is called a goiter.
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One advantage of this medication is that it has a lower risk of birth defects than another anti-thyroid drug known as methimazole or Tapazole, Endocrine Web noted.
Rx List added, however, that although pregnant women prescribed to use PTU can use it during the first three months of pregnancy, it is not recommended during the later six. The medication also can enter breast milk.
Drugs.com said PTU has been shown to cause damage to the baby during pregnancy.
PTU is only available in 50-milligram units, according to Endocrine Web. On average, it is taken three times a day, though patients should speak with their doctor about dosage first. Methimazole and Tapazole have more flexibility in dosage amounts.
Few patients — 1 percent to 3 percent — using anti-thyroid medications experience adverse side effects, Endocrine Web reported.
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Side effects include dizziness, drowsiness, headache, hair loss, muscle pain, and changes in taste, Drugs.com reported.
More serious side effects include persistent fatigue, liver problems, bruising and bleeding, severe allergic reactions, and symptoms of infections, according to Drugs.com.
Patients have reported serious liver problems, especially within the first few months of taking PTU, Endocrine Web reported. Issues such as stomach pains, yellowing of eyes or skin, or changes in appetite are serious and can be fatal.
Another rare condition that can develop is agranulocytosis, which is a problem for the blood and bone marrow and can also be life-threatening, according to Endocrine Web. The exact cause is unknown, but it attacks granulocytes, which are immune cells. This can lead to infection. Taking PTU over methaimazole puts a patient at a higher risk of developing this condition.
PTU may also decrease the number of platelets in the blood. For this reason, those taking the drug should avoid activities that could lead to bruising or bleeding, Drugs.com noted.
Endocrine Web added that such anti-thyroid medications may not work forever. Many doctors will recommend decreasing dosage over the course of months after treatment begins to become effective. The likelihood of side effects increases the longer a patient uses PTU.
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