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Why Do You Insist on Synthroid Instead of Armour? -- A Patient's Letter

Thanks to Shirley Grose, a thyroid patient, for sharing with us the following powerful letter she wrote to her doctor, after he insisted on prescribing Synthroid (a brand name synthetic levothyroxine sodium/T4 thyroid hormone replacement drug) instead of the Armour Thyroid (a brand name naturally derived T4/T3 drug) she'd been taking. (See "A Quick Look at Thyroid Hormone Replacement" for more about these different drugs.) Shirley's letter is strong and clearly asks many excellent questions many people want answered. She's generously agreed to allow her letter to be posted for other thyroid patients to read or modify for their use, in the hopes that it might help empower her fellow thyroid sufferers who are having the same problems with their doctors. (Note: Shirley's doctor never responded...)

Dear Doctor ______________:

I would like for you to clarify several points which came up during our recent discussion. You said Armour Natural Thyroid, my thyroid replacement preference, was impure, not predictably the same strength and old fashioned. I am concerned about this information because I have uncovered some research which indicates flaws in this reasoning.

Would you clarify your statements on Armour Natural Thyroid product? If you feel those statements were valid, can you provide documentation to confirm your opinion that Armour Thyroid is an inferior product to Synthroid? Is Synthroid really a "new " product or was it "grandfathered-in" around 1930? I would like to know, why, when I changed to Armour Natural Thyroid, you didn't consider the definite improvement in my health important? I would like to know why you felt I was unqualified to say how my own body felt? Why would you insist upon prescribing a drug that I have tried and does not work well with my body?

Why do you prescribe one drug for all patients? According to Dr. Stephen E. Langer's book Solved, The Riddle of Illness, "It is possible, because of the liver's role in the T-4 and T-3 conversion, to have an over-or under-conversion as a result of liver function." For some patients, Armour Thyroid, because it contains both T-3 and T-4, may provide the extra energy they need to stay employed, continue relationships, or feel good. Synthroid does not contain both, Synthroid has to convert to T3 from T4. Furthermore, author Dr. Ray Peat states, "Unfortunately, our physicians often fail to understand or explain the benefits of natural (marketed under the name 'Armour') over synthetic thyroid medication." Though the formula has changed somewhat in recent years, Dr. Peat calls the natural {thyroid} "the most generally effective," since "many people whose thyroids are suppressed by stress cannot respond to synthetic thyroxine, T4." Finally, is it possible that those impurities or unknowns you mentioned might possibly be as yet undiscovered substances which assist thyroid function, a substance or substances which cannot possibly exist in a synthetic product?

Your first statement during my consultation as a new patient was that the Armour Natural Thyroid should be discarded, it was full of impurities, it was of inconsistent strength and it "went out in the 70s." Synthroid was the drug of choice. Armour was clearly inferior. I explained that I felt better on the Armour Thyroid. You ordered me to throw the Armour Natural Thyroid away and take the Synthroid dosage you prescribed. You said that a TSH test would not be valid if taken while on Armour Natural Thyroid. Can you document this last statement? I understand the TSH is considered one objective measurement for thyroid supplementation; however, I question the inference that a patient's subjective opinion is unimportant. You seem to disregard how your patients feel. Have there been any major published studies indicating which product the health consumer preferred? Customers have apparently had no choice in thyroid medication in most instances. Therefore, sales volume is not indicative of customer preference. Also, does the Synthroid company fund or in any way contribute to organizations which you belong or to the university, itself? If so, does this influence your decision to singularly prescribe Synthroid?

At the end of my appointment, when you began to write my prescription for Synthroid, I indicated that would not be necessary. You asked, "Why?" I said I was continuing with the Armour Thyroid at the dosage my family physician had prescribed. Your response was, "You don't need to return do you?" I said, "No, I don't." You further explained you did not use the Armour Natural Thyroid, and you would not treat me if I continued taking it.

Do you refuse to treat thyroid cancer patients who refuse to take Synthroid? Should I develop thyroid cancer at some point in the future, would you refuse treatment to me on the basis that I chose not to take Synthroid? Can you legally refuse to treat a patient who has thyroid cancer because the patient takes Armour Natural Thyroid? Why should I or any patient be intimidated into taking what they feel is an inferior product. Why should I or any patient suffer a lesser quality of life because of physician bias for a particular brand name?

I called Forest Pharmaceuticals, Inc. the manufacturer's of Armour Natural Thyroid, and spoke to Neal Sailer, the Product Manager, Thyroid Products. He is sending a packet of documentation supporting the consistency of Armour Natural Thyroid.

He took exception that Armour Natural Thyroid is of "unpredictable variability." He explained that desiccated Thyroid powder is a U.S.P. product which means potency content is consistent and he added that the active drug product is constantly assayed during the entire manufacturing process, the FDA insists on this for all products. In addition, Mr. Sailer explained that samples from every batch are retained and periodically assayed for potency. I understand that the limit for T3 and T4 for U.S.P. Thyroid powder is 90% to 110% and natural thyroid is a more stable product than the synthetics. Mr. Sailer would like to know how you came to a determination of Armour being an "impure" or sub-potent drug substance, and would like to see your data. Are you suggesting that Armour Natural Thyroid be recalled?

Additionally, Mr. Sailer informed me of a study recently published in the Journal of the American Medical Association (JAMA), entitled Bioequivalence of Generic and Brand-name Levothyroxine Products in the Treatment of Hypothyroidism, by Betty J. Dong, PharmD; et. al. Are you familiar with the study? Why are you prescribing a product that is 50% more expensive than Levoxyl and Levothroid? Are you assured of the potency of Synthroid? I also understand that Synthroid was reformulated in 1982 because the potency of Synthroid was not near its stated content. In fact, in a letter from Dr. Betty Dong, to the editor of The Journal of Clinical Pharmacy, Dr. Dong assayed several 200 mg tablets of levothyroxine from several brands and generic and found Levothroid had 99% of it s stated potency content and Synthroid had only 78%. I understand that it was this information that prompted the reformulation of Synthroid. I also understand that patients were not informed of this change in formulation, which was clearly dangerous. Which now leads me back to the U.S.P. standard and something else I have learned about Synthroid.

Mr. Sailer informed me that Synthroid is failing the original U.S.P. standard for dissolution for levothyroxine preparations. It is also my understanding that they requested and were given a separate standard for dissolution by the U.S.P. which Mr. Sailer said was most unusual. If this separate dissolution standard for Synthroid is successfully challenged, Synthroid may have to once again reformulate. Will you or the public be informed if this happens? I understand also that there are several class action lawsuits pending against the makers of Synthroid probably initiated as a result of the several articles that appeared in the Wall Street Journal and news stories that were carried on NBC Nightly News. After all of the above, why did you insist on prescribing Synthroid? Could _________ University provide me with any information regarding support from the makers of Synthroid, whether it is Knoll or Boots or Flint?

I would sincerely appreciate an answer with documentation, in writing about the statements you have made about Synthroid and Armour Thyroid. I feel these are important questions, not only for me, but for the future physicians _______________ University educates. These future doctors, including the student who took my thyroid history, have not been given complete information which would allow them and their patients to make educated decisions about their health and their lives.


Shirley E. Grose

Synthroid and other Levothyroxine Sodium Preparations Found to Have Significant Stability and Potency Problems

When Shirley Grose wrote in this letter to her doctor, "Are you assured of the potency of Synthroid?" she was asking a question whose answer is just now now coming to light. On August 14, 1997, the U.S. Food and Drug Administration filed notice in the Federal Register that drugs containing levothyroxine sodium (such as Synthroid and other brand name and generic thyroid hormone preparations) are "new drugs." This means that these drugs will for the first time be required to submit new drug applications that formally document the drug's safety, effectiveness, and consistent potency.

This notice is in response to new information found by the government that shows significant stability and potency problems with orally administered levothyroxine sodium products. Also, these products do not remain potent through the expiration date, and tablets of the same dosage strength from the same manufacturer have been shown to vary from lot to lot in the amount of active ingredient present. The government found that this lack of stability and consistent potency has the potential to cause serious health consequences to the public. You can read more about this in an article here at the website.

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