Re: Thyroid +Mino

[Guest guest]

Ute,

Hyperthyroid means too much thyroid function, while hypothyroid means

too little thyroid function.

A brief Google search for

+thyroid +minocycline

brings up pages which include the following:

http://www.springerlink.com/content/0414432475vq7244/

http://www.liebertonline.com/doi/abs/10.1089/thy.2008.0048?cookieSet=1 & journalCo\

de=thy

http://www.archivesofpathology.org/doi/full/10.1043/1543-2165%282004%29128%3C355\

%3APQCTIP%3E2.0.CO%3B2

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1900569/

http://linkinghub.elsevier.com/retrieve/pii/S0149794401004767

The above links, as well as warning labels associated with

minocycline, indicate that minocycline is often associated with black

pigmentation of the thyroid gland and can be associated with hard

thyroid nodules and papillary carcinoma.

The page http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=6854

http://www.globalphar.com/PI/PI_Minocycline%20Hydrochloride.pdf

and other pages include the following text:

" Carcinogenesis, Mutagenesis, Impairment of Fertility

Dietary administration of minocycline in long term tumorigenicity

studies in rats resulted in evidence of thyroid tumor production.

Minocycline has also been found to produce thyroid hyperplasia in

rats and dogs. In addition, there has been evidence of oncogenic

activity in rats in studies with a related antibiotic,

oxytetracycline (ie, adrenal and pituitary tumors). Likewise,

although mutagenicity studies of minocycline have not been conducted,

positive results in in vitro mammalian cell assays (ie, mouse

lymphoma and Chinese hamster lung cells) have been reported for

related antibiotics (tetracycline hydrochloride and oxytetracycline).

Segment I (fertility and general reproduction) studies have provided

evidence that minocycline impairs fertility in male rats. "

Now to your main question. A brief Google search for

+thyroid +doxycycline

brings up pages which include the following:

http://www.ncbi.nlm.nih.gov/pubmed/16477607

http://www.rxlist.com/oracea-drug.htm (click on the 4th tab)

" Carcinogenesis, Mutagenesis, Impairment of Fertility. "

Both minocycline and doxycycline are tetracycline class drugs

antibiotics; however, there are many fewer web pages for doxycycline

on blackening of the thyroid and thyroid tumors than for minocycline.

I hope that this answers some of your questions.

Sincerely, Harald

At 04:06 PM 3/2/2010, Ute wrote:

>Hello Herald,

>I know you did a lot of research regarding thyroid and mino a while

>back. My latest blood test showed that my thyroid function is is on

>the upper range of normal for hyperthyroid. I am thinking of

>discontinuing the Mino for a while to see if that will come down. Do

>you know if Doxycyline has the same effect?

>Take care,

>Ute