Thyroid Tablets

26 October 2009

Products Affected - Description

Reason for the Shortage

• Several thyroid (desiccated) products have been discontinued. The manufacturers would not provide a reason for the discontinuations; however these products are not FDA-approved.
• Forest states that the shortage of Armour Thyroid is due to a shortage of raw material.¹
• RLC states the shortage is because of high demand for the product.²
• Major will not provide a reason for the shortage.³

Estimated Resupply Dates

• Thyroid (desiccated) products are not FDA-approved and therefore cannot be AB-rated.
• Major has available 120 mg tablets (100 count, NDC 00904-0762-60). All other presentations are on back order and the company cannot estimate a release date.³
• Forest has all Armour Thyroid presentations on back order and the company cannot estimate a release date.¹
• RLC has all presentations of Nature-Throid on back order and the company estimates a release date of late-November to early-December, 2009.²
• RLC also has all presentations of Westhroid on back order and the company cannot estimate a release date.²

Implications for Patient Care

• Desiccated thyroid is derived from porcine thyroid glands and contains both L-thyroxine (T₄) and liothyronine (T₃). Desiccated thyroid is labeled as replacement therapy for patients with hypothyroidism.^4,5
• Treatment guidelines from the American Association of Clinical Endocrinologists (2006) recommend levothyroxine as the preferred thyroid replacement product.^6,7,8
• Levothyroxine is a synthetic L-thyroxine (T₄) product labeled as replacement therapy for patients with hypothyroidism.^4,9

Safety

• During the shortage of desiccated thyroid products, patients may be tempted to use over the counter thyroid supplements. Caution patients that these products may contain bovine thyroid gland and there is a theoretical risk of mad cow disease from ingestion of these products.⁸
• Monitor patients for control of hypothyroidism when switching between products.

Alternative Agents & Management

• The thyroid products are not directly comparable because of lack of standardization of T₄ and T₃ content in the products.⁴
• Forest Laboratories provides a conversion guide for switching patients from one thyroid product to another.¹⁰ The Table summarizes the approximate dose equivalence between levothyroxine and desiccated thyroid. The equivalents are only estimates and patients may require individualized dosage adjustments.

Related Shortages

• Liothyronine Tablets— Resolved
• Liotrix Tablets

1. Forest (personal communications). August 21, October 2, November 4 and 25, and December 18, 2008; January 16, February 5 and 26, March 11 and 23, April 24, May 26, June 9, July 6 and 31, August 31, September 10 and 21, and October 12 and 26, 2009.
2. RLC (personal communications). August 21, October 2, November 4 and 25, and December 18, 2008; January 16, February 5 and 26, March 11 and 23, April 24, May 26, June 9, July 6 and31, August 31, September 10 and 21, and October 12 and 26, 2009.
3. Major (personal communications). August 21, October 2, November 4 and 25, and December 18, 2008; January 16, February 5 and 26, March 11 and 23, April 24, May 26, June 9, July 6 and31, August 31, September 10 and 21, and October 12 and 26, 2009.
4. Thyroid and Antithyroid Agents. In: McEvoy GK, Snow EK, Miller J, Kester L, Welsh OH, eds. AHFS 2009 Drug Information. Bethesda, MD: American Society of Health-System Pharmacists; 2009: 3314-3329.
5. Armour Thyroid (thyroid) tablets [product information]. St. Louis, MO: Forest Laboratories, August 2008.
6. Gharib H, Papini E, Valcavi R, et al. American Association of Clinical Endocrinologists and Associazione Medici Endocrinologi medical guidelines for clinical practice for the diagnosis and management of thyroid nodules. Endocr Pract. Jan-Feb 2006;12(1):63-102.
7. Baskin HJ, Cobin RH, Duick DS, et al. American Association of Clinical Endocrinologists medical guidelines for clinical practice for the evaluation and treatment of hyperthyroidism and hypothyroidism. Endocr Pract. Nov-Dec 2002;8(6):457-469.
8. Desiccated thyroid vs. synthetic thyroid supplementation. Pharmacist’s Letter/ Prescriber’s Letter 2008; 24 (10): 241013.
9. Levothroid (levothyroxine) tablets [product information]. St. Louis, MO: Forest Laboratories, September 2005.
10. Forest Laboratories. Switching to Armour. Accessed October 12, 2009.
    

Updated

Updated October 26, 2009 by Michelle Wheeler, Pharm.D., Drug Information Specialist, Drug Information Service.  Created October 2, 2009 by Jane Chandramouli, Pharm.D., Drug Information Specialist. Copyright 2009, Drug Information Service, University of Utah, Salt Lake City, UT.

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