MedicalTerminology DB
General Medical Terms

propylthiouracil

Meaning of propylthiouracil: A thiourea derivative with antithyroid property.

Definition of propylthiouracil

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.

Written and maintained by James Murray Last updated July 21, 2026 Educational reference, not medical advice. Read the limitations.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.