Desiccated thyroid extract

Desiccated thyroid extract (DTE), also known as thyroid extract, is a medication made from the dried thyroid glands of animals, primarily pigs. It is used to treat thyroid conditions, especially hypothyroidism, where the thyroid gland does not produce enough thyroid hormones. DTE contains both thyroxine (T4) and triiodothyronine (T3), which are hormones produced naturally by the thyroid gland in humans.

History

The use of desiccated thyroid extract dates back to the late 19th century, before synthetic thyroid hormones were available. It was one of the first effective treatments for hypothyroidism, providing a natural source of thyroid hormones. Over time, synthetic forms of T4 (levothyroxine) became more popular due to their consistency and ease of monitoring blood levels. However, some patients continue to prefer DTE, claiming better symptom relief compared to synthetic hormones.

Indications

Desiccated thyroid extract is indicated for the treatment of hypothyroidism, a condition characterized by insufficient production of thyroid hormones by the thyroid gland. Symptoms of hypothyroidism include fatigue, weight gain, cold intolerance, and depression. DTE is also used in some cases to treat goiter and thyroid cancer, although its use in these conditions is less common.

Pharmacology

DTE contains both T4 and T3, the two main hormones produced by the thyroid gland. The ratio of T4 to T3 in desiccated thyroid extract is approximately 4:1, which is similar to the ratio found in human thyroid secretion. However, this ratio may vary between different brands of DTE. The presence of both T4 and T3 is believed to provide a more comprehensive replacement therapy for hypothyroidism, as some patients do not efficiently convert T4 to T3.

Administration and Dosage

Desiccated thyroid extract is administered orally, usually once daily. The dosage is individualized based on the patient's clinical response and laboratory tests. Starting doses and maintenance doses can vary significantly among individuals. It is important for patients to work closely with their healthcare provider to find the optimal dose.

Side Effects

The side effects of desiccated thyroid extract are similar to those of other thyroid hormone replacement therapies and are typically related to overtreatment or undertreatment. Symptoms of overtreatment (hyperthyroidism) may include weight loss, palpitations, nervousness, and insomnia. Symptoms of undertreatment (continued hypothyroidism) include fatigue, weight gain, and cold intolerance. It is important to monitor thyroid function tests regularly to adjust the dose as needed.

Controversies and Considerations

There is ongoing debate among healthcare professionals about the use of desiccated thyroid extract versus synthetic thyroid hormones. Some studies suggest that certain patients may feel better on DTE, reporting improvements in mood and cognitive function. However, the American Thyroid Association and other medical organizations generally recommend synthetic thyroid hormones as the standard of care, citing the consistency and reliability of dosing.

Conclusion

Desiccated thyroid extract remains an option for the treatment of hypothyroidism, particularly for patients who do not feel well-controlled on synthetic thyroid hormone replacement. It is important for patients considering DTE to have a thorough discussion with their healthcare provider about the potential benefits and risks.