Thyroid Hormone Replacement: Pharmacology Made Easy & Clinical Relevant

This Is Why with Dr. Busti · Oct 6, 2025 · 44m

Levothyroxine is first-line for hypothyroidism, but getting it right requires precision. In this episode, Dr. Busti explains the TSH–T4–T3 feedback loop, why T4 is preferred over T3 or desiccated thyroid, and how half-life and protein binding shape dosing and monitoring. We cover steady-state timing (6–8 weeks), dose step sizes, manufacturer switches, and how food and cation supplements (calcium, iron, magnesium) alter absorption. You’ll also learn how anticonvulsants, rifampin, beta-blockers, steroids, and amiodarone affect levels or peripheral conversion.

Special populations receive focused…