Rapid Rx Quiz: Thyroid Drugs

Mary L. Windle, PharmD


July 20, 2022

A comparative effectiveness research study found that changing between different generic levothyroxine products did not cause clinically significant changes in TSH levels. Specifically, among 15,829 patients who filled a generic levothyroxine prescription, 83% who continued to use the same product experienced normal TSH levels compared with 85% of patients who switched between generic products. Researchers suggest this may free up patients and pharmacists to use the cheapest alternative. This is in conflict with current guidelines, which warn that using levothyroxine products from different manufacturers may cause potential changes in TSH levels.

Learn more about levothyroxine.


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