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Avatar universal

Can Antibiotics affect my thyroid tests?

Hi all,

I am 37 years old,had hashimoto since two years and was put on Euthyrox 75 since then which made my symptoms decrease.However,since a month I suffer from severe anxiety,feel cold all the time,have histamine issues, and have diarrhea and bloating when eating starches ( I am 100% gluten and dairy free). My doc requested full thyriod panel, CBC, and iron panel to be done as soon as possible but these days I take antibiotics due to bladder infection.Can antibiotics affect the results of these tests? Should I postpone the tests until I finish the antibiotics? If so, how long should I wait after finishing it?

Thanks in advance.
10 Responses
Avatar universal
Some patients notice an improvement in how they feel shortly after starting on thyroid med, but it doesn't last.  .  This is because the med starting dose is not additive to your prior levels.  The med causes your TSH to go down, which in turn provides less stimulation to the thyroid gland to produce hormone.   The net effect on serum levels is very little.  Only when the dose is high enough to essentially suppress TSH, will further increases in med dosage start to raise your thyroid hormone levels and have a lasting effect on symptoms.  

A word of caution though.  Most doctors don't understand that our bodies  normally get a continuous low flow of thyroid hormone in the untreated state, but when you take a significant dose of thyroid med all at once it spikes thyroid levels for a short time and suppresses TSH for the day.   Most doctors don't know about this and will diagnose a suppressed TSH as hyperthyroidism due to over medication and will want to reduce the med dosage.    You are actually hyperthyroid only if having hyper symptoms due to excessive levels of Free T4 and Free T3.    Knowing this will prepare you for future situations with the doctor.  

Even without knowing your new serum levels and the other tests, your symptoms are indicative of inadequate low thyroid, which I explained above.  You need to increase your med dosage, and may even need to add a source of T3 to your T4 med.  Most hypo patients taking T4 find that their Free T4 will eventually increase with dose increases, but due to poor conversion of T4 to T3, Free T3 is inadequate.  Researchers have found that on average, even at higher doses of T4, symptom relief required Free T3 in the upper half of its range.   A good thyroid doctor will diagnose and treat a hypothyroid patient based primarily on symptoms, supported with expanded testing that includes Free T4, Free T3, Vitamin D, B12 and ferritin.  So you should make sure all of those are tested at next opportunity.  

Regarding any effect from the antibiotic.  There is some evidence that antibiotic can affect thyroid gland function and cause lower thyroid levels, but a lot of your thyroid hormone is coming from the med now.    As for affecting the test itself I found this:

"Other medications can interfere with thyroid laboratory measurements, but not with the actual functioning of the thyroid.3

A few examples of these medications include:

Certain nonsteroidal anti-inflammatories (NSAIDs)
Certain anti-convulsants
Heparin (a blood thinner)
Lasix (furosemide)
Glucocorticoids
Isotretinoin

It didn't mention antibiotics, so I would not be concerned about it and go ahead and get the tests listed above done.  If you want confirmation of what I have said, click on my name and then on my personal page scroll down to my Journal and read at least the Overview of a paper on Diagnosis and Treatment of Hypothyroidism: A Patient's Perspective.  
Avatar universal
Some patients notice an improvement in how they feel shortly after starting on thyroid med, but it doesn't last.  .  This is because the med starting dose is not additive to your prior levels.  The med causes your TSH to go down, which in turn provides less stimulation to the thyroid gland to produce hormone.   The net effect on serum levels is very little.  Only when the dose is high enough to essentially suppress TSH, will further increases in med dosage start to raise your thyroid hormone levels and have a lasting effect on symptoms.  

A word of caution though.  Most doctors don't understand that our bodies  normally get a continuous low flow of thyroid hormone in the untreated state, but when you take a significant dose of thyroid med all at once it spikes thyroid levels for a short time and suppresses TSH for the day.   Most doctors don't know about this and will diagnose a suppressed TSH as hyperthyroidism due to over medication and will want to reduce the med dosage.    You are actually hyperthyroid only if having hyper symptoms due to excessive levels of Free T4 and Free T3.    Knowing this will prepare you for future situations with the doctor.  

Even without knowing your new serum levels and the other tests, your symptoms are indicative of inadequate low thyroid, which I explained above.  You need to increase your med dosage, and may even need to add a source of T3 to your T4 med.  Most hypo patients taking T4 find that their Free T4 will eventually increase with dose increases, but due to poor conversion of T4 to T3, Free T3 is inadequate.  Researchers have found that on average, even at higher doses of T4, symptom relief required Free T3 in the upper half of its range.   A good thyroid doctor will diagnose and treat a hypothyroid patient based primarily on symptoms, supported with expanded testing that includes Free T4, Free T3, Vitamin D, B12 and ferritin.  So you should make sure all of those are tested at next opportunity.  

Regarding any effect from the antibiotic.  There is some evidence that antibiotic can affect thyroid gland function and cause lower thyroid levels, but a lot of your thyroid hormone is coming from the med now.    As for affecting the test itself I found this:

"Other medications can interfere with thyroid laboratory measurements, but not with the actual functioning of the thyroid.3

A few examples of these medications include:

Certain nonsteroidal anti-inflammatories (NSAIDs)
Certain anti-convulsants
Heparin (a blood thinner)
Lasix (furosemide)
Glucocorticoids
Isotretinoin

It didn't mention antibiotics, so I would not be concerned about it and go ahead and get the tests listed above done.  If you want confirmation of what I have said, click on my name and then on my personal page scroll down to my Journal and read at least the Overview of a paper on Diagnosis and Treatment of Hypothyroidism: A Patient's Perspective.  
1 Comments
Thanks gimel for your quick response and valuable info.I also feel I need to increase my dose and wait for the tests to confirm.As for T3 medication,no doc in my country prescribe it and no pharmacy have it. Unfortunately,we have only Euthyrox.I will do the tests and post the results here to review and     tell me your opinion.

Thanks again.
Avatar universal
My results are below:

Free T3:  2.31 (Ref range: 1.7- 4.2)
Free T4:  0.84 (Ref range: 0.75- 1.56)
TSH: 0.856   (Ref range: 0.55- 4.78)

CBC results:

RBC show mild microcytosis and anisocytosis
Mild relative lymphocytosis
Mild absolute neutropenia

My doc refused at any case to increase my dose as he told me that my TSH is perfect and any increase in dose will make me hyper.I told him that my Free T4 is in the floor of its range but he dose not seem concerned.Also he said I had anemia and need iron supplements.What do you think about my thyriod tests and CBC.Should I increase my dose to alleviate my symptoms or this will made me hyper?. If not ,how much can I increase? Can I increase by 12.5 mcg?
Avatar universal
What test results made the doctor say you need iron supplements?
1 Comments

The CBC result which shows mild microcytosis and anisocytosis.He said this indicates iron deficiency.
Avatar universal
Let's make sure that no symptoms are overlooked.  Please review the following list used by the Mayo Clinic and tell us which ones you have.  Then I will have suggestions for your next appointment with the doctor.

Fatigue
Increased sensitivity to cold  (temp. below 98.6 which is considered normal)
Constipation  ( had to use fiber or laxatives before you had surgery)
Dry skin (have to use moisturizer)
Weight gain  (you previously had this problem, so it is a yes)
Puffy face    (I think you had this problem before surgery, but hard to notice now with your weight loss)
Hoarseness
Muscle weakness
Elevated blood cholesterol level
Muscle aches, tenderness and stiffness
Pain, stiffness or swelling in your joints
Heavier than normal or irregular menstrual periods
Thinning hair
Slowed heart rate
Depression
Impaired memory
Enlarged thyroid gland (goiter)
insomnia/sleep apnea
1 Comments
Sorry.I do not understand.what surgery? I did not have surgery before and I did not suffer from weight gain.
Avatar universal
Sorry, I copied a list  of symptoms I used for someone else, with my comments.  Here, I'll try again.  Please tell us about any of these you have.

Fatigue
Increased sensitivity to cold  (temp. below 98.6 which is considered normal)
Constipation  ( have to use fiber or laxatives)
Dry skin (have to use moisturizer)
Weight gain  
Puffy face    
Hoarseness
Muscle weakness
Elevated blood cholesterol level
Muscle aches, tenderness and stiffness
Pain, stiffness or swelling in your joints
Heavier than normal or irregular menstrual periods
Thinning hair
Slowed heart rate
Depression
Impaired memory
Enlarged thyroid gland (goiter)
insomnia/sleep apnea
1 Comments
I wonder why is Mayo clinic listed those only for hypo symptoms. I am sure hypo can cause a ton of symptoms other than this. Also, one of my symptoms is on the contrary to what it is listed.I have severe diarrhea to the extent that I went yesterday to the ER because I had to do a trip to the bathroom every 10-15 minutes. They found that I suffer bad dehydration and take potassium IV to replace the electrolytes I lost from diarrhea. When I came back home and called my doc, he told me that diarrhea had nothing to do with my hypo  !!!! I never suffer from this before hashimoto. Can it be a hashimoto thing no hypo thing?

As for other symptoms I suffer and listed above I have fatigue, increased sensitivity to cold, puffy face, muscle aches, Enlarged gland. I have others but not listed above.
Avatar universal
Not by any stretch is that a complete list of hypothyroid symptoms.  It is just some of the most typical ones.   Your symptom of diarrhea could be due to a number of possible causes.   Is this something that has occurred only recently?  Do you have any of the following additional symptoms?

extreme fatigue
weight loss and decreased appetite
darkening of your skin
low blood pressure
salt craving
abdominal pain nausea, diarrhea or vomiting
muscle or joint pains
irritability
depression or other behavioral symptoms
body hair loss

With your symptoms and your test results, it is obvious to you and us that you need an increase i your thyroid medication.  To get the doctor to do this is the problem because he doesn't understand how TSH is affected by taking a significant dose all at once instead of the continuous low flow of thyroid hormone in the untreated state.    I think you have to ask him if your TSH is perfect why do you still have all those symptoms that are typical of hypothyroidism, and give him a list of all symptoms that you have.  Then tell him that there is extensive scientific data showing that typically when taking a full daily replacement dose all at once, adequate to relieve symptoms, the TSH becomes suppressed; however, that does not mean hyperthyroidism, unless you have hyper symptoms due to excessive levels of Free T4 and Free T3.    I have a study showing that when a dose of thyroid med that causes suppression of TSH, is split into thirds and taken over the entire day, instead of all at once, it will raise the TSH by about 2.  So TSH suppression is usually caused by the dosing procedure being so different from the normal low flow of thyroid hormone, not the dose amount.   I can give you a copy of this by email, if you want it for your doctor.  I can also send you a copy of a graph showing the effect of Free T3 on the incidence of hypothyroid symptoms.  

I also suggest that you click on my name and then scroll down ot my Journal and read at least the Overview of my paper on Diagnosis and Treatment of Hypothyroidism: A Patient's Perspective.  It will be very useful info for you, and a copy for your doctor might get him to reconsider his decision about dosage.  

1 Comments
Thanks gimel. Yes, my diarrhea increased recently with low blood pressure
salt craving, and abdominal pain nausea. Is these  symptoms of adernal fatigue? I surely will ask my doc to test me for adernal fatigue as I read there is a connection between thyriod and adernal glands.

Thank you also for clarifying the reason of TSH is suppressed when I take the whole of my dose one time in the morning. I now completely understand this and I will discuss with my doc all this and if he is still not convinced, I will get back to you to give me the link of this study.
Avatar universal
Those symptoms are from the Mayo Clinic's list of symptoms typical of hypocortisolism.    Low cortisol is a common problem for women with hypothyroidism.    The best way to test for it is a saliva cortisol (free cortisol) panel of 4 tests taken at different times of the day.   Doctors usually will not order saliva cortisol tests.  Instead they will run a morning serum cortisol (total cortisol) test, which is not nearly as revealing as the saliva tests.   In either case the reference ranges used by labs are likely to be calculated based on all tests at the lab.  Since they have no ready method for identifying only healthy adults with no cortisol pathology, the ranges are far too broad and especially skewed to the low end.    So with those symptoms if your cortisol test results are in the lower half of the range it is worth a conversation with the doctor about a trial of cortisol med.

When are you scheduled for followup tests and an appointment with the doctor?
1 Comments
Cortisol med means steroids? I tried steriods many times to help my inflammation caused by hashimoto and I felt awful on them. I think about natural methods to help my adernal like adernal cooktail or any pills for adernal support if the cortisol tests indicates I am deficient. My appointment with my doc is on 1 March.
Avatar universal
Cortisol is a type of steroid; however I can't imagine trying to reduce inflammation from Hashi's by using a steroid.   The correct approach would have been to use thyroid medication adequate for a full daily replacement amount.  That would have reduced the antibodies of Hashi's.  

Your body produces steroids all day.  If your production is too low that causes problems  and requires replacement.   Thyroid hormone needs to be somewhat balanced with cortisol.  Cortisol needs to be somewhat balanced by DHEA.   If it turns out that you need cortisol then you should not be concerned about a trial of hydrocortisone (and DHEA).    This is a natural approach.   Taking an adrenal support is unlikely to achieve the desired result.   For example, how much would you need and what is the actual effect of all that is in the supplement?   Much better to rely on actual cortisol (and DHEA).

I am also sending you a PM.  To access, just click on your name and then from your personal page click on messages.
1 Comments
Thank you gimel. I will respond to your message.I took steriods because of a severe hashi flare up which caused my thyriod to be swollen and my temperature to be high. I do not think levo could no any thing about this. But steriods, especially Prednisone made me awful ( high blood pressure, weight gain, etc). I will discuss with my doc any method other than steroids. I hope I can find alternatives.
Avatar universal
Prednisone is a lousy steroid because of the side effects.   You can get the same good effect with hydrocortisone, and prevent unwanted side effects by also taking DHEA.  
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