USE OF CHOLESTYRAMINE AS ADJUNCT FOR HYPERTHYROIDISM – A META-ANALYSIS

Abstract

INTRODUCTION
Hyperthyroidism is defined as a state produced by excessive thyroid function. Such can lead to thyrotoxicosis which is defined as a state of excessive thyroid hormone. There are several etiologies of thyrotoxicosis, all of which are due to hyperthyroidism. In a state of thyrotoxicosis, there is an increased production and metabolism of thyroid hormones leading to an increase in its enterohepatic circulation. Cholestyramine is generally used for the treatment of hypercholesterolemia; however, it can also be used as an adjunctive therapy for hyperthyroidism by decreasing gut reabsorption and increasing excretion of thyroid hormones.

OBJECTIVE
To assess evidence from randomized controlled trials (RCTs) regarding the efficacy of using Cholestyramine as an adjunct to anti-thyroid medications in its effect to decrease Total T3 and FT4 levels in hyperthyroid patients.

METHODOLOGY
A review of articles using PubMed and Cochrane (CENTRAL) was done. Search terms used were cholestyramine, bile acid binding resin, hyperthyroidism, Graves’ disease. Randomized controlled trials were evaluated regarding the effect of cholestyramine as an adjunct to standard treatment. Studies included are limited to randomized controlled trials, with patients of interest are those diagnosed with hyperthyroidism. Studies were assessed for risk of bias and data extraction was done by primary author and reviewed with co-author. Data analysis was done, summary statistics using mean difference, and forest plots were generated using Review Manager 5.3. Publication bias was no longer assessed due to the limited number of studies in this meta-analysis.

RESULTS
Data was collected from 4 randomized controlled trials. There was a decrease in Total T3 (MD=45.55; 95% CI: 33.65, 57.46) which was 45.55 units lower in the cholestyramine as an adjunct compared to standard treatment alone. After addressing heterogeneity, mean difference further increased to 74.89. There was also a decrease in FT4 levels (MD=0.65; 95% CI: -1.39, 0.08) which is 0.65 units lower for those treated with cholestyramine as an adjunct compared to standard treatment alone.

CONCLUSION
Results showed that treatment with cholestyramine as an adjunct to standard therapy can lead to greater decrease in Total T3 and FT4 hormones in hyperthyroid patients.