How should I write a prescription order for Armour Thyroid (natural desiccated thyroid) 60 mg for a patient with hypothyroidism?

How to Write a Prescription Order for Armour Thyroid 60 mg

Critical Safety Warning Before Prescribing

Do not prescribe Armour Thyroid or any desiccated thyroid product—levothyroxine (synthetic T4) is the only recommended treatment for hypothyroidism. 1

Armour Thyroid lacks standardization in T3 content and creates dangerous pharmacokinetic profiles that significantly increase cardiovascular and bone health risks compared to levothyroxine monotherapy. 2

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Why Armour Thyroid Should Not Be Prescribed

Lack of Standardization and Safety Concerns

• Armour Thyroid has inconsistent T3 content between batches, making reliable dosing impossible and increasing the risk of iatrogenic hyperthyroidism. 2

• The combination of T4 and T3 in desiccated thyroid creates supraphysiologic T3 peaks that do not occur with levothyroxine monotherapy, potentially causing cardiac complications including atrial fibrillation, myocardial infarction, and sudden cardiac death. 2

• One case report documented a 32-year-old male on 120 mg daily Armour Thyroid who developed an acute myocardial infarction with complete occlusion of the left anterior descending artery, attributed to the hypercoagulable and hypofibrinolytic state induced by excessive thyroid hormone. 2

Guideline Recommendations Against Desiccated Thyroid

• Levothyroxine monotherapy is the standard of care for hypothyroidism, with decades of clinical experience and FDA approval supporting its safety and efficacy. 1

• Current guidelines universally recommend levothyroxine as first-line therapy, with no major endocrine society endorsing desiccated thyroid products for routine use. 1

• The American Thyroid Association and other guideline societies consistently recommend against combination T4/T3 therapy or desiccated thyroid for standard hypothyroidism treatment. 1

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If You Must Write This Prescription (Against Medical Advice)

Prescription Format

If the patient absolutely insists despite counseling, and you document this as against medical advice:

Armour Thyroid 60 mg (1 grain)
Take 1 tablet by mouth once daily on an empty stomach, 30-60 minutes before breakfast
Dispense: 90 tablets
Refills: 2

Critical Monitoring Requirements

• Recheck TSH and free T4 (and free T3) in 4-6 weeks after initiation, as the T3 component creates rapid changes in thyroid status that require closer monitoring than levothyroxine alone. 1

• Monitor for symptoms of hyperthyroidism including tachycardia, tremor, heat intolerance, weight loss, palpitations, and anxiety—these occur more frequently with desiccated thyroid than levothyroxine. 1

• Obtain baseline ECG and repeat if TSH becomes suppressed, as the T3 component significantly increases atrial fibrillation risk, particularly in patients over 60 years or with cardiac disease. 1

Target TSH Range

• Target TSH should be 0.5-4.5 mIU/L with normal free T4 and free T3 levels—TSH suppression below 0.1 mIU/L increases atrial fibrillation risk 3-5 fold and fracture risk in postmenopausal women. 1

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Proper Alternative: Levothyroxine Prescription

Standard Levothyroxine Dosing

• For patients under 70 years without cardiac disease, start levothyroxine at approximately 1.6 mcg/kg/day (typically 100-125 mcg daily for average-weight adults) to rapidly normalize thyroid function. 1

• For patients over 70 years or with cardiac disease, start at 25-50 mcg daily and titrate gradually by 12.5-25 mcg increments every 6-8 weeks to avoid unmasking cardiac ischemia or precipitating arrhythmias. 1

Levothyroxine Prescription Format

Levothyroxine 100 mcg
Take 1 tablet by mouth once daily on an empty stomach, 30-60 minutes before breakfast
Dispense: 90 tablets
Refills: 11

Monitoring Protocol

• Recheck TSH and free T4 every 6-8 weeks during dose titration until TSH reaches target range of 0.5-4.5 mIU/L, then monitor annually or with symptom changes. 1

• Once adequately treated, repeat testing every 6-12 months or sooner if clinical status changes. 1

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Patient Counseling Points

Administration Instructions

• Take levothyroxine on an empty stomach, at least 30-60 minutes before breakfast, and at least 4 hours apart from iron, calcium supplements, or antacids to maximize absorption. 1

• Liquid levothyroxine formulations may be taken 15 minutes before meals with similar bioavailability to the standard 30-minute interval, potentially improving adherence. 3

• Bedtime dosing of levothyroxine (at least 2 hours after the last meal) results in lower TSH levels and higher free T4 and T3 levels compared to morning dosing, though quality of life measures show no significant difference. 4

Critical Safety Information

• Never start thyroid hormone before ruling out adrenal insufficiency in patients with suspected central hypothyroidism, as this can precipitate life-threatening adrenal crisis. 1, 5

• Approximately 25% of patients on levothyroxine are unintentionally maintained on doses sufficient to fully suppress TSH, increasing risks for atrial fibrillation, osteoporosis, fractures, and cardiovascular mortality. 1

• Prolonged TSH suppression below 0.1 mIU/L increases atrial fibrillation risk 3-5 fold in patients over 45 years and fracture risk in women over 65 years. 1