Low Doses of Cholestyramine in the Treatment of Hyperthyroidism

This study has been completed.
Sponsor:
Information provided by:
Shiraz University of Medical Sciences
ClinicalTrials.gov Identifier:
NCT00677469
First received: May 12, 2008
Last updated: May 13, 2008
Last verified: May 2008
  Purpose

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


Condition Intervention
Graves Disease
Drug: Cholestyramine
Drug: Placebo powder

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
Official Title: Low Doses of Cholestyramine in the Treatment of Hyperthyroidism

Resource links provided by NLM:


Further study details as provided by Shiraz University of Medical Sciences:

Enrollment: 45
Study Start Date: July 2007
Study Completion Date: January 2008
Primary Completion Date: January 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: I
Cholestyramine 2g BID, Methimazole 10mg TID, and Propranolol 20mg BID
Drug: Cholestyramine
2 grams BID
Experimental: II
Cholestyramine 1g BID, Methimazole 10mg TID, and Propranolol 20mg 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

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.

  Eligibility

Ages Eligible for Study:   20 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Patients with newly diagnosed hyperthyroid Graves' disease

Exclusion Criteria:

  • If the patient had been treated previously
  • diabetes, kidney, or liver disease
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00677469

Locations
Iran, Islamic Republic of
Endocrine and Metabolism Research Center
Shiraz, Fars, Iran, Islamic Republic of
Sponsors and Collaborators
Shiraz University of Medical Sciences
Investigators
Study Chair: Golamhossein Omrani, M.D. Endocrine and Metabolism Research Center
  More Information

No publications provided by Shiraz University of Medical Sciences

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Golamhossein Ranjbar Omrani, Endocrine and Metabolism Research Center
ClinicalTrials.gov Identifier: NCT00677469     History of Changes
Other Study ID Numbers: 2590
Study First Received: May 12, 2008
Last Updated: May 13, 2008
Health Authority: Iran: Ministry of Health

Keywords provided by Shiraz University of Medical Sciences:
Hyperthyroidism
Cholestyramine

Additional relevant MeSH terms:
Graves Disease
Hyperthyroidism
Exophthalmos
Orbital Diseases
Eye Diseases
Goiter
Thyroid Diseases
Endocrine System Diseases
Autoimmune Diseases
Immune System Diseases
Cholestyramine Resin
Anticholesteremic Agents
Hypolipidemic Agents
Antimetabolites
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Lipid Regulating Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on April 17, 2014