Propylthiouracil

**Semantic type:** Nucleic Acid, Nucleoside, or Nucleotide|Pharmacologic Substance

**Definition:** A thiourea derivative with antithyroid property. Propylthiouracil (PTU) interferes with the oxidation of iodine possibly by interaction with peroxidase or a peroxidase-mediated complex reaction, thereby inhibiting synthesis of thyroid hormones tri-iodothyronine (T3) and thyroxine (T4). In addition, this agent inhibits the Type I 5'-deiodinase (D1), an enzyme involved in the peripheral conversion of thyroxine to tri-iodothyronine. This results in decreased plasma triodothyronine concentrations and decreased entrance of thyroxine into cells thereby reducing thyroid hormone activity.

**Synonyms:** - 6-Propyl-2-Thiouracil - 6-Propyl-2-thiouracil - PROPYLTHIOURACIL