Treatment Overview

Hypothyroidism

Following a diagnosis of hypothyroidism, treatment involves thyroid hormone replacement. There are many options in this area, including:1

  • synthetic L-thyroxine (T4)
    • (e.g. synthroid, levoxyl and unithroid)
       
  • synthetic L-triiodothyronine (T3)
    • (e.g. cytomel)
       
  • synthetic T4/T3 combinations
    • (e.g. thyrolar)
       
  • desiccated thyroid preparations
    • (e.g. armour, naturethroid, bio-throid, and westhroid)
       


Administration of T3 therapy only can lead to peaks and troughs of thyroid hormone levels immediately after and preceding therapy. As T4 is generally more stable than T3 and can be broken down to the biologically more active T3, most endocrinologists will prescribe T4 therapy for patients with hypothyroidism, in order to maintain acceptable levels of both T3 and T4.

 For more information see:

Hyperthyroidism

Following a diagnosis of hyperthyroidism, treatment usually involves counteracting the production or effects of excessive thyroid hormone production either pharmacologically, radiotherapeutically, or surgically.



Antithyroid drugs typically make it more difficult for the body to manufacture thyroid hormones by affecting its ability to use iodine.2 There are three key antithyroid drugs:

  • methimazole (tapazole): inhibits the addition of iodine to thyroglobulin3
  • propylthiouracil (PTU; generic formulations only): has two effects; inhibition of the thyroid glands use of iodine to produce thyroid hormone, and inhibition of the conversion of T4-to-T3 
  • carbimazole (neo-mercazole): a prodrug that metabolizes to methimazole


For more information see:

In many countries, including the USA, radioactive iodine treatment/ablation is a common procedure for most people with Graves’ disease and hyperthyroidism.4 A single dose of Iodine-131 is administered and subsequently accumulates in the thyroid, damaging and destroying the thyroid cells and thereby modifying thyroid function. Following radioactive iodine treatment, patients will usually require thyroid hormone replacement therapy.



Thyroidectomy is often considered the last choice in the US for treating an overactive thyroid.5 However, surgical treatment may be recommended if:

  • other treatments have been ineffective
  • thyroid cancer is suspected
  • the patient is experiencing difficulty in breathing/swallowing
  • the patient is pregnant
     

References

  1. Drugs.com. Underactive Thyroid (Hypothyroidism) Medications. Accessed 26 April 2011.
  2. Abraham P, Avenell A, McGeoch SC, Clark LF, Bevan JS. Antithyroid drug regimen for treating Graves’ hyperthyroidism. Cochrane Database Syst Rev. 2010;20(1):CD003420.
  3. Ferreira AC, de Carvalho Cardoso L, Rosenthal D, et al. Thyroid Ca2+/NADPH-dependent H2O2 generation is partially inhibited by propylthiouracil and methimazole. Eur J Biochem. 2003;270(11):2363-23668.
  4. DeGroot LJ. Thyroid Disease Manager. 2010;Chapter 11.
  5. American Thyroid Association and American Association of Clinical Endocrinologists: Treatment Guidelines for Patients with Hyperthyroidism