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Study says warfarin–levothyroxine interaction insignificant, but questions remain


In older adults who had received warfarin for at least 90 days, there was no association between hospitalization for hemorrhage and initiation of levothyroxine in the previous 30 days, according to a recent study. However, study limitations prevented definite conclusions regarding clinical significance of these findings.


Pincus D et al. A population-based assessment of the drug interaction between levothyroxine and warfarin. Clin Pharmacol Ther. 2012;92:766–70.

Clinical Pharmacology [database online]. Tampa, FL: Gold Standard, Inc. 2013. Accessed April 14, 2013.