What adjustments should be made to the current levothyroxine (T4) medication regimen, with the patient taking 60 mg of Armor (levothyroxine) in the morning and 15 mg in the evening, given the lab results showing elevated Total T3 and Free T3, elevated Reverse T3, and normal Thyroid-Stimulating Hormone (TSH) levels?

From the Guidelines

I would recommend reducing your Armour Thyroid dosage due to elevated T3 levels, specifically decreasing your total daily dose from 75 mg to approximately 60 mg total, with 45 mg in the morning and 15 mg in the afternoon, as your current dosage appears to be causing overtreatment. Your TSH is within normal range but at the upper limit, while your Free T3 is significantly elevated at more than twice the upper limit of normal, and your Reverse T3 is also elevated, which can indicate that your body is having trouble properly utilizing the thyroid hormone, as seen in patients with similar profiles 1. Armour Thyroid contains both T4 and T3, and your body appears to be accumulating excess T3.

• Key points to consider:
  • Your TSH level is 4.16, which is within the normal range but on the higher end, suggesting that your thyroid function is at the lower end of normal.
  • Your Free T4 level is normal, which indicates that you are not deficient in T4.
  • Your Total T3 and Free T3 levels are elevated, indicating that you have excess T3 in your system.
  • Your Reverse T3 level is also elevated, which can indicate that your body is converting too much T4 to Reverse T3 instead of active T3. Considering the guidelines for thyroid hormone replacement therapy, a dose reduction is warranted to avoid overtreatment and potential adverse effects. The guideline suggests that for patients without risk factors, full replacement can be estimated using ideal body weight for a dose of approximately 1.6 mcg/kg/d, but in your case, a reduction from the current dose is necessary to normalize your thyroid hormone levels 1. After making this change, you should retest your thyroid levels in 6-8 weeks to assess the effect of the dose reduction. If symptoms of hypothyroidism develop with the reduced dose, you might need to consider switching to a different thyroid medication that contains less T3 component, such as Synthroid (levothyroxine).

From the FDA Drug Label

The dose of Levothyroxine Sodium Tablets, USP that is adequate to achieve these goals depends on a variety of factors including the patient's age, body weight, cardiovascular status, concomitant medical conditions, including pregnancy, concomitant medications, and the specific nature of the condition being treated The levothyroxine sodium dose is generally adjusted in 12.5-25 mcg increments until the patient with primary hypothyroidism is clinically euthyroid and the serum TSH has normalized. In patients with severe hypothyroidism, the recommended initial levothyroxine sodium dose is 12.5-25 mcg/day with increases of 25 mcg/day every 2-4 weeks, accompanied by clinical and laboratory assessment, until the TSH level is normalized.

The patient's current labs show elevated Total T3 and Free T3 levels, as well as elevated Reverse T3. The TSH level is 4.16, which is within the normal range. Given the patient's current medication regimen of 60 mg Armor in the morning and 15 mg Armor in the PM, and considering the elevated T3 levels, it is likely that the patient is experiencing overtreatment. To adjust the medication, the dose of levothyroxine sodium should be decreased in 12.5-25 mcg increments, with periodic assessment of the patient's clinical response and laboratory parameters, until the patient is clinically euthyroid and the serum TSH has normalized 2. It is also important to monitor the patient's cardiovascular status, as overtreatment with levothyroxine sodium may have adverse cardiovascular effects 2.

From the Research

Medication Adjustment

To adjust the medication based on the provided lab results, we need to consider the following factors:

• TSH level: 4.16 (.45-4.5) Normal
• T4 level: 8.1 (normal)
• T3 uptake: 28% (24%-39%)
• Total T3: 289 (elevated)
• Free T3: 9 (elevated)
• Reverse T3: 28.9 (elevated)
• Free T4: 1.46 (normal)

Considerations for Adjustment

The following points should be considered when adjusting the medication:

• The patient is currently taking 60 mg Armor in the morning and 15 mg Armor in the PM.
• The elevated Total T3 and Free T3 levels may indicate that the patient is taking too much T3 or that their body is converting T4 to T3 too efficiently 3.
• The elevated Reverse T3 level may indicate that the patient's body is converting T4 to Reverse T3 instead of T3, which could be due to various factors such as non-thyroidal illness syndrome or certain medications 4.
• The normal TSH and Free T4 levels suggest that the patient's thyroid hormone levels are within the normal range, but the elevated T3 and Reverse T3 levels need to be addressed.

Potential Adjustments

Based on the provided evidence, potential adjustments to the medication could include:

• Decreasing the dose of Armor to reduce the elevated T3 levels 3.
• Considering the addition of a medication that inhibits the conversion of T4 to Reverse T3, such as a deiodinase inhibitor 4.
• Monitoring the patient's lab results closely to ensure that any adjustments to the medication do not cause adverse effects or interactions with other medications 5.
• Consulting with a pharmacist or a healthcare professional to determine the best course of action for adjusting the medication regimen 5.