MedicineNet.com
About Us | Privacy Policy | Site Map
November 24, 2009
MedicineNet home Picture Slideshows Diseases and conditions Symptoms and signs Procedures and tests Medications Health and Living Picture Image Collection MedTerms medical dictionary
Font Size
A
A
A

Hypothyroidism (cont.)

How is hypothyroidism treated?

With the exception of certain conditions, the treatment of hypothyroidism requires life-long therapy. Before synthetic levothyroxine (T4) was available, desiccated thyroid tablets were used. Desiccated thyroid was obtained from animal thyroid glands, which lacked consistency of potency from batch to batch. Presently, a pure, synthetic T4 is widely available. Therefore, there is no reason to use desiccated thyroid extract.

As described above, the most active thyroid hormone is actually T3. So why do physicians choose to treat patients with the T4 form of thyroid? T3 [liothyronine sodium (Cytomel)] is available and there are certain indications for its use. However, for the majority of patients, a form of T4 [levothyroxine sodium (Levoxyl, Synthroid)] is the preferred treatment. This is a more stable form of thyroid hormone and requires once a day dosing, whereas T3 is much shorter-acting and needs to be taken multiple times a day. In the overwhelming majority of patients, synthetic T4 is readily and steadily converted to T3 naturally in the bloodstream, and this conversion is appropriately regulated by the body's tissues.

  • The average dose of T4 replacement in adults is approximately 1.6 micrograms per kilogram per day. This translates into approximately 100 to 150 micrograms per day.

  • Children require larger doses.

  • In young, healthy patients, the full amount of T4 replacement hormone may be started initially.

  • In patients with preexisting heart disease, this method of thyroid replacement may aggravate the underlying heart condition in about 20% of cases.

  • In older patients without known heart disease, starting with a full dose of thyroid replacement may result in uncovering heart disease, resulting in chest pain or a heart attack. For this reason, patients with a history of heart disease or those suspected of being at high risk are started with 25 micrograms or less of replacement hormone, with a gradual increase in the dose at 6 week intervals.

Ideally, synthetic T4 replacement should be taken in the morning, 30 minutes before eating. Other medications containing iron or antacids should be avoided, because they interfere with absorption.

Therapy for hypothyroidism is monitored at approximately six week intervals until stable. During these visits, a blood sample is checked for TSH to determine if the appropriate amount of thyroid replacement is being given. The goal is to maintain the TSH within normal limits. Depending on the lab used, the absolute values may vary, but in general, a normal TSH range is between 0.5 to 5.0uIU/ml. Once stable, the TSH can be checked yearly. Over-treating hypothyroidism with excessive thyroid medication is potentially harmful and can cause problems with heart palpitations and blood pressure control and can also contribute to osteoporosis. Every effort should be made to keep the TSH within the normal range.



Next: What is subclinical hypothyroidism? »

Hypothyroidism - Symptoms Experienced

The MedicineNet physician editors ask:

For hypothyroidism, what were the symptoms and signs you experienced?

Comment submissions for this question have ended. Patient Discussions FAQs
See 30 Viewer Comments

View Comments


Printer-Friendly Format  |  Email to a Friend


Suggested Reading by Our Doctors
MedicineNet Doctors
  • levothyroxine sodium, Synthroid, Levoxyl, Levothroid, Unithroid - Learn more about Levothyroxine Sodium (Synthroid, Levoxyl, Levothroid, Unithroid), including a description, generic and brand names, drug class and mechanism, preparations, storage, reasons for prescription, dosing, drug interactions, effect on pregnancy and nursing mothers, and common side effects.
  • Thyroid Blood Tests - Read about thyroid blood tests, which are used to diagnose disease of the thyroid such as hyperthyroidism and hyperthyroidism, as well as point to other diseases of the thyroid gland.
  • Stress - Read about stress symptoms, signs, causes and treatment. Get information on stress management tips, the effects on the body and stress types (teen, job, PTSD).

Latest Medical News


Women's Health

Find out what women really need.


Are you Depressed? Take the Quiz

Your Guide to Symptoms & Signs: Pinpoint Your Pain












Health categories:

Slideshows | Diseases & Conditions | Symptoms & Signs | Procedures & Tests | Medications | Health & Living | News & Views | Medical Dictionary

Popular health centers:

Allergies | Arthritis | Cancer | Diabetes | Digestion | Healthy Kids | Heart | Men's Health | Mental Health | Women's Health | More...

Publications:

ePublications (PDFs) | XML News via RSS | Audio Podcasts | Email Newsletters

MedicineNet.com:

About Us | Privacy Policy | Site Map | WebMD® | Medscape® | eMedicine® | eMedicineHealth® | RxList®

This website is certified by Health On the Net Foundation. Click to verify. This site complies to the HONcode standard for trustworthy health information:
verify here.

©1996-2009 MedicineNet, Inc. All rights reserved. Notices and Legal Disclaimer.
MedicineNet does not provide medical advice, diagnosis or treatment. See additional information.