Dr. Ron Cobbs, Noted Endocrinologist, Speaks Out

We welcome a contribution from Dr. Ron Cobbs.

Dr. Ron Cobbs and I go way back. We knew eachother when he was finishing his endocrinology fellowship at LIJ Medical Center on Long Island in the 80’s. Later he worked as an attending Endocrinologist at a New York City Hospital when I was the Director of an endocrine training program in another part of the city.

Ron leaves his opinion (below) for us to ponder on the subject of thyroid hormone replacement therapy. I guess Ron and I will just have to disagree about the use of Armour thyroid but we both recognize the value of adding t3 (Cytomel) to traditional pure t4 (Synthroid) therapy in selected individuals who need more complex replacement therapy to achieve a good clinical response.

Thanks Ron for your comments!


Dr. Cobbs writes:

Several points should be noted. The American Assciation of Clinical Endocrinologists (AACE) recommends against the use of dessicated thyroid preparations. They specifically recommend levothyroxine and preferably branded versions as small changes in concentration have marked differences in clinical effects and blood test results such as TSH and free T4. Further, the endocrine literature reports that although most patients are successfully treated with branded levothyroxine alone, there is a small minority who never feel back to normal. However the literature supports the addition of T3 in the form of Cytomel rather than to retreat to the non-precise dessicated thyroid preparations of the past.

An experienced endocrinologist familiar with the literature can by precribing branded levothyroxine be able to treat most of their hypothyroid patients to the satisfaction of both phyician and patient. However the endocrinologist must listen to their patients and follow thyroid function blood tests. Even when the blood tests are normal, if the patient still does not feel normal again, the careful addition of amounts of T3 (cytomel) to the thyroxine will usually help the rest to feel better again.

Also remember to avoid taking iron replacement and medications such as cholestyramine or colesevelam too close to the levothyroxine as they prevent the adequate absortion of levothyroxine in the body.

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  • Amy

    Perhaps this letter should end with:

    “And the patients who don’t feel better again despite the administration of branded T4 and T3 preparations are probably just “complainers” and should be told to eat less, exercise more, and be treated for their lingering hypothyroid symptoms with antidepressants, statins, laxatives, hysterectomies, moisturizers, heavy sweaters, wigs, and pain medications.”

    Why is it that the “branded levothyroxine/Citomel” promoters do not address the fact that synthetic preparations do not include all the thyroid hormones naturally occurring in desiccated thyroid preparations? Is it because no randomized double blinded placebo controlled study has yet been done to determine the usefulness of T1, T2 and calcitonin on the human body therefore it’s assumed that these hormones normally secreted by our thyroids are not necessary and just an accident of nature? Please tell me this isn’t so.
    Thank you for publishing this letter. I will avoid Drs like Dr Cobbs in the future.