Effect of Metformin on Decrement in Levothyroxin Dose Required for Thyroid Stimulating Hormone (TSH) Suppression in Patients With Differentiated Thyroid Cancer

Mashhad University of Medical Sciences

Status: Completed

Conditions: Malignant Neoplasm of Thyroid Stage I; Malignant Neoplasm of Thyroid Stage II

Treatments: Drug: Metformin

Study type: Interventional

Funder types: Other

Identifiers

NCT01341886

METTC

Details and patient eligibility

About

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.

Enrollment: 51 patients

Sex: All

Ages: Under 80 years old

Volunteers: No Healthy Volunteers

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)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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51 participants in 2 patient groups, including a placebo group

metformin

Active Comparator group

Description:

patients who receive metformin in addition to levothyroxine

Treatment:

Drug: Metformin

levothyroxine

Placebo Comparator group

Description:

patients who receive only levothyroxine

Treatment:

Drug: Metformin