Drugs That May Cause Protein-Binding Site Replacement And Drugs That May Either Increase Or Decrease Serum TBG-Concentration
Levothyroxine has a narrow therapeutic index and being a drug that is administered in chronic form; there is a high risk of its interaction with different drugs that could be simultaneous administration with it when it is under use for the treatment of hypothyroidism. Levothyroxine in different steps of its pharmacokinetic could interact with various drugs.
Because thyroid hormone is highly protein bound, medical conditions that alter the amount of binding hormones and drugs that compete for binding may change the amount of available free thyroid hormone. The thyroid replacement dosage must be changed in response to both alterations in binding status and alterations in amounts of transport proteins.