Hypothyroidism (underactive thyroid)
Standard treatment for hypothyroidism involves daily use of the synthetic thyroid hormone levothyroxine (Levothroid, Synthroid, others). This oral medication restores adequate hormone levels, reversing the signs and symptoms of hypothyroidism.
One to two weeks after starting treatment, you’ll notice that you’re feeling less fatigued. The medication also gradually lowers cholesterol levels elevated by the disease and may reverse any weight gain. Treatment with levothyroxine is usually lifelong, but because the dosage you need may change, your doctor is likely to check your TSH level every year.
Determining proper dosage may take time
To determine the right dosage of levothyroxine initially, your doctor generally checks your level of TSH after two to three months. Excessive amounts of the hormone can cause side effects, such as:
- Increased appetite
- Heart palpitations
If you have coronary artery disease or severe hypothyroidism, your doctor may start treatment with a smaller amount of medication and gradually increase the dosage. Progressive hormone replacement allows your heart to adjust to the increase in metabolism.
Levothyroxine causes virtually no side effects when used in the appropriate dose and is relatively inexpensive. If you change brands, let your doctor know to ensure you’re still receiving the right dosage. Also, don’t skip doses or stop taking the drug because you’re feeling better. If you do, the symptoms of hypothyroidism will gradually return.
Proper absorption of levothyroxine
Certain medications, supplements and even some foods may affect your ability to absorb levothyroxine. Talk to your doctor if you eat large amounts of soy products or a high-fiber diet or you take other medications, such as:
- Iron supplements or multivitamins that contain iron
- Aluminum hydroxide, which is found in some antacids
- Calcium supplements
If you have subclinical hypothyroidism, discuss treatment with your doctor. For a relatively mild increase in TSH, you probably won’t benefit from thyroid hormone therapy, and treatment could even be harmful. On the other hand, for a higher TSH level, thyroid hormones may improve your cholesterol level, the pumping ability of your heart and your energy level.
Although most doctors recommend synthetic thyroxine, natural extracts containing thyroid hormone derived from the thyroid glands of pigs are available. These products contain both thyroxine and triiodothyronine. Synthetic thyroid medications contain thyroxine only, and the triiodothyronine your body needs is derived from the thyroxine.
Extracts are available by prescription only and shouldn’t be confused with the glandular concentrates sold in natural foods stores. These products aren’t regulated by the Food and Drug Administration, and their potency and purity isn’t guaranteed.