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Generic Name: Thyroid hormones
Brand Name(s):
Information updated: April 1, 2000
Overview
Thyroid hormones come in a variety of formulations and brand names.
Natural products made of dried thyroid glands from beef and pork are
sold as Armour Thyroid, Thyroid Strong and Thyroid USP.
They are
generally quite inexpensive, but dosage levels may vary. That is why
endocrinologists usually prescribe synthetic products such as Synthroid or
Levothroid.
When people develop a sluggish thyroid gland they often feel
tired and weak. They may become constipated, sensitive to cold or anemic.
They may also suffer with dry skin and hair, thick brittle fingernails
and have shortness of breath when they exercise.
Some people report
clumsiness, weight gain, or puffy eyes.
Thyroid problems are diagnosed
with blood tests. The best is one that measures thyroid stimulating hormone, or
TSH.
This test also helps determine the proper dose of thyroid hormone
for treatment.
Side Effects and Interactions
Side effects of thyroid replacement therapy are
rare if the dose is appropriate.
Specialists recommend beginning
treatment with a low dose and gradually increasing it until symptoms of
underactive thyroid disappear and the TSH blood test is normal.
This may
initially require blood tests every four to six weeks and good communication
with the doctor.
Too much thyroid hormone can lead to complications such
as osteoporosis and heart disease.
Signs of overdose include insomnia,
heart palpitations, jitteriness, rapid heart beat, increased sweating, higher
blood pressure, changes in appetite, and reduced menstrual flow.
Other
adverse reactions of excessive thyroid levels include tremor, headache,
diarrhea, and weight loss. Report any such symptoms to your physician
promptly.
A number of medications may interact with thyroid hormone or
alter the tests that detect thyroid problems.
People taking estrogen,
asthma medicines, decongestants (including those found in over-the-counter cold
or flu remedies), antidepressants, certain cholesterol lowering drugs, blood
thinners such as Coumadin or heart medicine like digoxin should check with a
physician or pharmacist.
In theory, the herb guggul might counteract
thyroid-suppressing drugs or increase the effect of thyroid hormones. Monitoring
thyroid function is prudent.
Licorice may alter the required dose of
levothyroxine because of its impact on the thyroid gland.
Never stop
taking thyroid hormone without first checking with your health care
provider.
Special Precautions
Too much thyroid hormone can make a person more susceptible to osteoporosis or weakened bones.
You may wish to discuss with your doctor whether you need tests to monitor bone density.
Thyroid replacement is usually needed for the rest of one's life, and stopping the medicine suddenly could precipitate symptoms of inactive thyroid.
Don't discontinue any thyroid hormone without your doctor's supervision. It is usually best to stick with one formulation rather than switching from one brand to another frequently.
Taking the Medicine
The usual recommendation is to take thyroid hormone before breakfast.
Although this
hormone is probably best taken on an empty stomach, it is more important to take it at the same
time every day to maintain a constant level in your body.
Do not take this medication with
iron pills, as they can interfere with proper absorption.
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Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Their syndicated radio show can be heard on public radio.
© 2000
Reader Comments
When I was diagnosed with underactive thyroid, I was prescribed Synthroid. This did not seem to work well for me, so I switched to Armour Thyroid, which other than the smell was working well for me.
I had moved and although my new doctor kept me on Armour, she thought it best if I went with the Synthroid as it was easier to control.
I do not feel as well. I am always cold, dry hair and skin. I am also taking Allegra, Nexium, Lovaza, Zoloft, Zocor, Boniva and Metoprolol. Most are the Generic Brand. I also take Citracal, Vitamin D, Centrum Silver and Ester C. I occasionally have a dizzy spell and unsteady on my feet.
Should I go back to Armour?
What are the interactions between all these meds and vitamins? Thank you for your response.
Posted by: JCR | May 5, 2008 10:15 AM