For information on that enzyme family, see Iodotyrosine deiodinase. Pharmacokinetics
The administration is oral, with peak serum concentrations occurring in one hour, and actively concentrated to the thyroid gland. Depending on several patient variables, however, euthyroid status may not be achieved until 2–4 months after treatment initiation. 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. However, both are equally transferred across the placenta.The plasma half-life is one hour and is not altered appreciably by the thyroid status of the patient. Due to the concentration in the thyroid, however, dosing intervals may last 8 hours or longer. Less than 10% of the drug is excreted unchanged, with the remaining fraction undergoing extensive hepatic metabolism via glucuronidation. Chemical synthesis
Propylthiouracil can be prepared from ethyl 3-oxohexanoate and thiourea. Role in taste
Propylthiouracil, together with phenylthiocarbamide (PTC), are known to have bitter taste. However, it seems the propensity for tasting these compounds is genetically based and the bitter taste is likely to be engendered by the thiocyanate moiety, also present in PTC. History
It was approved by the United States Food and Drug Administration in 1947. References
External links

"Propylthiouracil". Drug Information Portal. U.S. National Library of Medicine.
Pregnancy
Anti-platelet autoantibodies in a pregnant woman with ITP will attack the patients own platelets and will also cross the placenta and react against fetal platelets. Therefore, ITP is a significant cause of fetal and neonatal immune thrombocytopenia. Approximately 10% of newborns affected by ITP will have platelet counts <50,000/uL and 1% to 2% will have a risk of intracerebral hemorrhage comparable to infants with neonatal alloimmune thrombocytopenia (NAIT).No lab test can reliably predict if neonatal thrombocytopenia will occur. The risk of neonatal thrombocytopenia is increased with:
Mothers with a history of splenectomy for ITP
Mothers who had a previous infant affected with ITP
Gestational (maternal) platelet count less than 100,000/uLIt is recommended that pregnant women with thrombocytopenia or a previous diagnosis of ITP should be tested for serum antiplatelet antibodies. A woman with symptomatic thrombocytopenia and an identifiable antiplatelet antibody should be started on therapy for their ITP which may include steroids or IVIG. Fetal blood analysis to determine the platelet count is not generally performed as ITP-induced thrombocytopenia in the fetus is generally less severe than NAIT. Platelet transfusions may be performed in newborns, depending on the degree of thrombocytopenia. It is recommended that neonates be followed with serial platelet counts for the first few days after birth. History
After initial reports by the Portuguese physician Amato Lusitano in 1556 and Lazarus de la Rivière (physician to the King of France) in 1658, it was the German physician and poet Paul Gottlieb Werlhof who in 1735 wrote the most complete initial report of the purpura of ITP.