[3] Common side effects include itchiness, hair loss, parotid swelling, vomiting, muscle pains, numbness, and headache.

[citation needed] Other common side effects are swelling, nausea, vomiting, heartburn, loss of taste, joint or muscle aches, numbness and headache, allergic reactions, and hair whitening.

"[7] As a result, propylthiouracil is no longer recommended in non-pregnant adults and in children as the front line antithyroid medication.

Symptoms and signs of agranulocytosis include infectious lesions of the throat, the gastrointestinal tract, and skin with an overall feeling of illness and fever.

Side effects are suspected and the drug is sometimes discontinued if the patient complains of recurrent episodes of sore throat.

[8] The primary effect on the fetus from transplacental passage of PTU is the production of a mild hypothyroidism when the drug is used close to term.

The hypothyroid state may be observed as a goiter in the newborn, and is the result of increased levels of fetal pituitary thyrotropin.

[12] PTU does not inhibit the action of the sodium-dependent iodide transporter located on follicular cells' basolateral membranes.

Of note, the drug is approximately 70% protein-bound and significantly ionized at normal physiologic pH, while the antithyroid agent methimazole is substantially less protein bound.

Less than 10% of the drug is excreted unchanged, with the remaining fraction undergoing extensive hepatic metabolism via glucuronidation.