Low Doses of Cholestyramine in the Treatment of Hyperthyroidism

May 13, 2008 updated by: Shiraz University of Medical Sciences
The enterohepatic circulation of thyroid hormones is increased in thyrotoxicosis.Bile-salt sequestrants (ionic exchange resins) bind thyroid hormones in the intestine and thereby increase their fecal excretion. Based on these observations, the use of cholestyramine has been tried. The present study evaluates the effect of low doses of cholestyramine as an adjunctive therapy in the management of hyperthyroidism

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The gastrointestinal tract has a role in thyroid physiology. Thyroid hormone is metabolized mainly in the liver, where it is conjugated to glucurunides and sulfates. These conjugation products are then excreted in the bile. Free hormones are released in the intestine and finally reabsorbed, completing the enterohepatic circulation of thyroid hormone. A very small portion of the daily production of thyroxin (T4) and triiodothyronine (T3), less than 10 percent, is excreted in the stool (1-3). In people with normal thyroid function, this pathway of T4 and T3 recirculation contributes so little to hormone availability that patients who have gastrointestinal disease or are receiving drugs that decrease T4 absorption do not have abnormal thyroid function (4). However, the thyrotoxic states are characterized by an increased enterohepatic circulation of thyroid hormones, as well as an increased urinary and fecal excretion of both conjugated and free T4 (5,6).

Cholestyramine, an ionic exchange resin sequesters T4 in the intestine and increases its fecal excretion. These phenomena were proven in hamsters in mid 1960s (7). Experimentally, it has been shown that 50 mg of cholestyramine can bind approximately 3000 μg of T4 (8) and therefore can enhance the clearance of thyroid hormones. Because of the increased enterohepatic circulation of thyroid hormones during hyperthyroidism, attempts have been made to sequester these hormones in the intestine using ionic exchange resins (9-13). Cholestyramine therapy has been studied in the treatment of thyrotoxicosis as an adjunctive therapy to thionamides, and has been found to decrease thyroid hormone levels rapidly. In several trials, cholestyramine in combination with methimazole (MMI) or propylthiouracil, caused a more rapid decline in thyroid hormone levels than standard therapy with thionamides alone (9-11,13). In all of these trials, cholestyramine was dosed at 4 grams orally two to four times a day.

This study was conducted to examine the efficacy of combination therapy of lower doses of cholestyramine with MMI and propranolol for treating patients with Graves' hyperthyroidism.

Study Type

Interventional

Enrollment (Actual)

45

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years to 60 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with newly diagnosed hyperthyroid Graves' disease

Exclusion Criteria:

  • If the patient had been treated previously
  • diabetes, kidney, or liver disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: I
Cholestyramine 2g BID, Methimazole 10mg TID, and Propranolol 20mg BID
Drug: Cholestyramine
2 grams BID
Drug: Cholestyramine
1 gram BID
Experimental: II
Cholestyramine 1g BID, Methimazole 10mg TID, and Propranolol 20mg BID
Drug: Cholestyramine
2 grams BID
Drug: Cholestyramine
1 gram BID
Placebo Comparator: III
Placebo powder 1g BID, Methimazole 10mg TID, and Propranolol 20mg BID
Drug: Placebo powder
1 gram BID

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Shiraz University of Medical Sciences

Investigators

  • Study Chair: Golamhossein Omrani, M.D., Endocrine and Metabolism Research Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2007

Primary Completion (Actual)

January 1, 2008

Study Completion (Actual)

January 1, 2008

Study Registration Dates

First Submitted

May 12, 2008

First Submitted That Met QC Criteria

May 13, 2008

First Posted (Estimate)

May 14, 2008

Study Record Updates

Last Update Posted (Estimate)

May 14, 2008

Last Update Submitted That Met QC Criteria

May 13, 2008

Last Verified

May 1, 2008

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2590

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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