Generic Name: thyroid desiccated

Brand Names: Armour Thyroid, Nature-Throid

Drug Class: Thyroid Products

What is thyroid desiccated, and what is it used for?

Thyroid desiccated is a dried form of thyroid, a naturally occurring hormone, used for replacement or supplemental therapy in people deficient in thyroid hormone (hypothyroidism).

Desiccated thyroid is produced from dried and powdered thyroid glands of animals, usually pigs. Desiccated thyroid contains thyroxine (T4) and triiodothyronine (T3), the two thyroid hormones produced by the thyroid gland, a butterfly-shaped endocrine gland located at the base of the neck.

Thyroid hormones have many important functions including regulation of metabolic rate, body temperature regulation, growth and development, and affect virtually every body organ. Untreated hypothyroidism slows down metabolism and energy expenditure, and causes weight gain and a host of other symptoms including fatigue and depression. Desiccated thyroid increases the basal metabolic rate, increases utilization and mobilization of glycogen stores, and promotes the generation of glucose that provides energy to the cells.

In addition to the treatment of hypothyroidism, desiccated thyroid is also used off-label in certain diagnostic tests related to thyroid function. Desiccated thyroid is a prescription drug that has been in use since the early 1890s. Animal thyroid extracts were never approved by the FDA as their use in the U.S. predates the FDA.

Levothyroxine, the synthetic form of thyroid T4 has since become more popular, however, in some people with hypothyroidism, T4 does not seem to get converted to T3, the form that cells in the body use. In such patients, desiccated thyroid appears more useful because it contains both T3 and T4 hormones, as well as small amounts of thyroid co-factors T1, T2, calcitonin, and iodine, all of which are essential to carry out normal thyroid functions in the body.

Warnings

  • Do not use in patients hypersensitive to any component in the desiccated thyroid extract.
  • Do not use desiccated thyroid in the following conditions:
    • Uncorrected adrenocortical insufficiency
    • Untreated thyrotoxicosis, a condition with excessively high levels of circulating thyroid hormones (T3 and/or T4) from any cause.
  • Desiccated thyroid therapy is not recommended in elderly patients.
  • Desiccated thyroid treatment for obesity in patients without hypothyroidism using doses within the range of daily requirements is ineffective for weight reduction. Larger doses may lead to serious or even life-threatening toxicity, particularly when given in combination with certain appetite-suppressing drugs (sympathomimetic amines).
  • Desiccated thyroid is ineffective in the treatment of infertility without hypothyroidism.
  • Thyroid replacement therapy may aggravate symptoms in patients with adrenal insufficiency, which should be first treated with glucocorticoid therapy.
  • The therapy of myxedema coma, a rare complication of hypothyroidism requires simultaneous administration of glucocorticoids.
  • Use desiccated thyroid with caution in patients with cardiovascular disease, hypertension, angina and endocrine disorders.
  • Use with caution in diabetes mellitus and insipidus, desiccated thyroid may aggravate symptoms.
  • Judicious use in acute myocardial infarction complicated or caused by hypothyroidism may be considered.
  • Hypothyroidism decreases and hyperthyroidism increases the sensitivity to oral anticoagulants. Prothrombin time should be monitored in patients and anticoagulant dosages should be adjusted appropriately.
  • Thyroid replacement therapy is essentially for life, except for transient hypothyroidism usually associated with thyroid inflammation (thyroiditis). Monitor thyroid levels periodically and advise patients to report if they experience symptoms of thyroid toxicity.

QUESTION

Where is the thyroid gland located? See Answer

What are the side effects of thyroid desiccated?

Common side effects of thyroid desiccated include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

What are the dosages of thyroid desiccated?

Tablet

  • 15 mg, 16.25 mg, 30 mg, 32.5 mg, 48.75 mg, 60 mg, 65 mg, 81.25 mg, 90 mg, 97.5 mg, 113.75 mg
  • 120 mg, 130 mg, 146.25 mg, 162.5 mg, 180 mg, 195 mg, 240 mg, 260 mg, 300 mg, 325 mg

Adult:

Hypothyroidism

  • Mild: initial 15-30 mg orally every day, may increase by 15 mg/day every 2-3 weeks (or 30 mg/day every 30 days)
  • Myxedema: Start 15 mg orally every day, then after 2 weeks 30 mg every day, then after 2 weeks 60 mg orally every day
  • Maintenance: 60-120 mg orally every day
  • Administration: before breakfast

Other Indications and Uses

  • As diagnostic agents in suppression tests to differentiate suspected mild hyperthyroidism or thyroid gland autonomy

Dosing Considerations

  • Readjustment of thyroid hormone dosage should be made within the first four weeks of therapy, after proper clinical and laboratory evaluations, including serum levels of T4, bound and free, and TSH
  • Desiccated thyroid form contains variable amounts of T3, T4, and other triiodothyronine compounds which are more likely to cause signs or symptoms due to fluctuating levels

Geriatric:

  • Not recommended

Pediatric:

Hypothyroidism

  • Children 6 months: 4.8-6 mg/kg orally every day  
  • Children 6-12 months: 3.6-4.8 mg/kg orally every day  
  • Children 1-5 years: 3-3.6 mg/kg orally every day  
  • Children 6-12 years: 2.4-3 mg/kg orally every day  
  • Children 12 years or older: 1.2-1.8 mg/kg orally every day  

Overdose

  • Desiccated thyroid overdose can increase the rate of metabolic activity resulting in a state of hypermetabolism with increase in resting energy expenditure, body temperature, heart rate and blood pressure, protein and fat breakdown (catabolism).
  • Treatment of desiccated thyroid overdose includes reduction in dosage or temporary discontinuation of the drug, with reinstatement of treatment with a lower dosage after symptoms subside.
  • Treatment of severe, acute overdosage may include:
    • Inducing vomiting to eliminate undigested drug in the gastrointestinal tract, provided gagging reflex is present and the patient is not in a convulsive or comatose state.
    • Symptomatic and supportive treatment with intravenous medications and fluids, and monitoring vital signs.

SLIDESHOW

Hyperthyroidism: Symptoms, Treatment, Medication See Slideshow

What drugs interact with thyroid desiccated?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Severe interactions of thyroid desiccated include:
    • sodium iodide I-131
  • Serious interactions of thyroid desiccated include:
    • antithrombin alfa
    • antithrombin III
    • argatroban
    • bemiparin
    • bivalirudin
    • dalteparin
    • enoxaparin
    • fondaparinux
    • heparin
    • lycopus
    • phenindione
    • protamine
  • Moderate interactions of thyroid desiccated include:
  • Thyroid desiccated has mild interactions with at least 26 different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

Pregnancy and breastfeeding

  • Hypothyroidism affects fertility and thyroid replacement with desiccated thyroid is recommended in infertile women of child-bearing age who wish to become pregnant, to normalize thyroid function and reproductive capacity.
  • Desiccated thyroid has not been found to cause fetal harm, and thyroid replacement therapy to hypothyroid women should not be discontinued during pregnancy.
  • Natural (endogenous) thyroid hormones are minimally present in breast milk and desiccated thyroid has not been found to be associated with adverse events in the breastfed infant. Use desiccated thyroid with caution in nursing mothers.

What else should I know about thyroid desiccated?

  • Take desiccated thyroid exactly as prescribed.
  • Thyroid replacement therapy is usually for lifetime. Follow up with your doctor for periodic assessment of thyroid status.
  • Report to your physician if you experience symptoms of thyroid toxicity, such as chest pain, increased pulse rate, palpitations, excessive sweating, heat intolerance, nervousness, or any other unusual event.
  • Keep safely out of reach of children.
  • In case of overdose, seek medical help or contact Poison Control.

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Summary

Thyroid desiccated is a dried form of thyroid, a naturally occurring hormone, used for replacement or supplemental therapy in people deficient in thyroid hormone (hypothyroidism). Common side effects of thyroid desiccated include chest pain, palpitations, irregular heart rhythm (cardiac arrhythmia), high heart rate (tachycardia), shortness of breath (dyspnea), abdominal cramps, diarrhea, constipation, vomiting, weight loss, increased appetite, excessive sweating (diaphoresis), hair loss (alopecia), fever, headache, heat intolerance, muscle pain (myalgia), cramps, impaired balance/coordination/speech (ataxia), tremor, and others. Consult your doctor if pregnant or breastfeeding.

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Medically Reviewed on 10/4/2022
References
https://www.rxlist.com/consumer_armour_thyroid_nature-throid/drugs-condition.htm

https://reference.medscape.com/drug/armour-thyroid-thyroid-usp-thyroid-desiccated-342736

https://www.uptodate.com/contents/thyroid-extract-desiccated-thyroid-drug-information

https://go.drugbank.com/drugs/DB09100

https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=eb240853-b036-43f0-816f-981c6d4fdfb4&type=display

https://www.endocrineweb.com/conditions/hypothyroidism/natural-thyroid-extract-comeback