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Letters to the Editor: Antibiotics and Microbiome, Hormone Panel

September 2015

Antibiotics and Microbiome

I had a few questions after reading the “Editor’s Memo” in the June issue of Practical Pain Management.1 Dr. Tennant mentions treatment aimed at over-activated glial cells. In the use of tetracyclines, in what time frame do you begin to see results?

Do these medications (tetracycline and minocycline) cross the blood/brain barrier to work on central glial cells? I have also been reading in The New York Times about the gut microbiome, and how antibiotics (or adding specific probiotics) can lower symptoms of other diseases (depression, anxiety).2

I wasn’t thinking so much of an antibiotic messing up intestinal flora (though that of course is of concern), but wondering if minocycline acts centrally or could it perhaps work indirectly by changing intestinal flora. The New York Times article discusses neurotransmitter release by intestinal flora, and that by changing gut flora, this changes neurotransmitter levels (gut-brain connection).2

I would be interested in your thoughts on this.

Sarah M. Whitman, MD

Clinical Assistant Professor

Department of Psychiatry

Drexel University
College of Medicine

Philadelphia, Pennsylvania

Dear Dr. Whitman,

Your interest and concern about the use of antibiotics to modulate glial cells are most appropriate. I have had patients respond to minocycline within 24 hours, but most patients report positive effects, if they’re going to get them, within the first week. I stop minocycline if they don’t get a response after a month.

Your concern about intestinal flora is most cogent. Also monilial overgrowth may occur.

Besides minocycline, I have a patient with arachnoiditis who reduced her pain about 30% with a single, daily dose of clarithromycin.

At this time I’m unable to determine the length of time patients should remain on an antibiotic. Due to their complications, I am leaning toward intermittent use and drug holidays, rather than elimination or perpetual administration. I am also using ketorolac on an intermittent and drug holiday basis in severe pain cases.

Unfortunately, some agents that really benefit some centralized, intractable pain patients have such side effects that they can’t be used daily.

I assume minocycline crosses the blood-brain barrier only because some centralized pain patients respond to it. There are now several studies showing that minocycline has a direct inhibiting effect on microglial cells. These studies have been done on in-vitro preparations and animals. Since I, like you, am a clinician, I’m not exactly certain how the basic science researchers do these studies or prepare the cellular materials.

Your thoughts about the “biome” (intestinal flora) is a most interesting idea that we shouldn’t simply discard.

Forest Tennant, MD, DrPH

Hormone Panel

I was wondering the appropriate method to order your 8 hormone panel for a female patient of mine who has suffered with chronic knee osteoarthritis pain for some time and continues to have some mood issues.What would be the appropriate diagnostic codes and in your experience have these tests been covered by Medicare? Additionally, will a compounding pharmacy be needed to prepare most of the replacement therapies identified in the lab panel?

Joseph V. De Santi, MD

York, Pennsylvania

Dear Dr. De Santi,

I have had no trouble getting lab tests covered by third party coverage, including Medicare. I simply bill the pain diagnoses first. My patients all have centralized pain (338.0) and chronic pain syndrome (338.4). In addition, I bill one or more hormone diagnoses as applicable to the patient. This may be hypogonadism, pituitary-adrenal insufficiency, or other.

As far as replacement, I have some hormones compounded. Dehydroepiandrosterone (DHEA) and pregnenolone can be purchased in a health food store. I use standard pharmaceutical estradiol, progesterone, hydrocortisone, and testosterone preparations.

Forest Tennant, MD, DrPH

Last updated on: September 14, 2015
First published on: September 1, 2015
Continue Reading:
Microglial Modulators: A New Therapeutic Class