Everything about PTU

This episode reviews the clinical pharmacology of propylthiouracil and its evolution in modern endocrinology practice. We examine its history from its discovery in the 1940s to its replacement by methimazole as the preferred first-line antithyroid therapy. The discussion covers the unique dual mechanism of propylthiouracil, focusing on both thyroid peroxidase inhibition and the inhibition of peripheral conversion of thyroxine to triiodothyronine via type one deiodinase. We analyze the essential clinical exceptions where propylthiouracil remains mandatory, specifically thyroid storm and first-trimester pregnancy management. Finally, we address serious toxicity profiles including severe hepatotoxicity, agranulocytosis, and antineutrophil cytoplasmic antibody associated vasculitis.