Registered Nurse (RN) Endocrine Licensure Practice Exam

Propylthiouracil (PTU) is the medication typically initiated for a pregnant patient diagnosed with hyperthyroidism during the first trimester due to its lower risk of fetal complications compared to alternative treatments. PTU is preferred because it inhibits the synthesis of thyroid hormones and has a relatively safer profile for the developing fetus, particularly in the early stages of pregnancy when the risk of teratogenic effects is heightened with certain medications.

Other options, such as radioactive iodine, are contraindicated during pregnancy because they can harm the fetal thyroid and cause permanent hypothyroidism in the infant. Tapazole, while effective, is often avoided during the first trimester due to potential risks of causing congenital anomalies. Synthroid, which is levothyroxine, is generally used to treat hypothyroidism, not hyperthyroidism. Therefore, PTU is the most suitable and commonly used medication in this specific scenario.