Effect of Metformin on Decrement in Levothyroxin Dose Required for Thyroid Stimulating Hormone (TSH) Suppression in Patients With Differentiated Thyroid Cancer
Effect of Metformin on Decrement in Levothyroxin Dose Required for Thyroid Stimulating Hormone (TSH) Suppression in Patients With Differentiated Thyroid Cancer
Differentiated thyroid cancer is the most common neoplasm of endocrine system. After surgery
 and radioiodine treatment, thyroid stimulating hormone (TSH) suppression is the main goal
 which is achieved with levothyroxine treatment. Levothyroxine causes increased thyroid
 hormones which can have negative impact on bone and cardiovascular system. Anecdotal reports
 have shown that metformin can induce TSH suppression without change in T3 and T4
 concentration. The purpose of this study was to prescribe metformin as additional drug to
 levothyroxin in order to decrease levothyroxine dosage.
Inclusion Criteria:

 -  papillary or follicular thyroid cancer

 -  stage 1 or 2 according to TNM system version 6

 -  surgery and radioiodine treatment

 -  levothyroxine suppression treatment

 Exclusion Criteria:

 -  cardiopulmonary failure

 -  liver failure

 -  renal failure

 -  pregnancy

 -  drugs (colestyramin, sucralfate, phenobarbital, phenytoin, carbamazepin, rifampin,
 amiodarone, chloroquin, androgens, sertraline, frusemide, heparin)