Thyroid hormone replacement therapy is used to replace thyroid hormone when the thyroid is underactive or not producing. The most often used medication for this condition is L-thyroxine (also know as LT4 or levothyroxine). This medication (synthetic) comes under many brand names including Levothyroid, Levoxyl, Tirosint, Unithyroid and Synthroid. There is another medication, dessicated thyroid, which is made from dehydrated porcine (pig) or bovine (cow) thyroid.
There are four main types of hypothyroidism. Hashimoto’s thyroiditis is most common cause. It is manifested by antibodies (produced by one’s own system) that attack the thyroid and destroy the gland. Congenital hypothyroidism is present at birth. Surgical removal of the thyroid due to disease such as cancer creates a need for thyroid replacement. (If only a part of the thyroid is removed, the remaining segment may produce enough thyroid hormone.) Another important cause is reduced intake of iodine that can cause inflammation and destruction of the thyroid. Lack of or reduced iodine intake can cause the acquisition by the thyroid of the contaminants chlorine, bromine and fluoride. This occurs because these chemicals are closely related to iodine. These contaminants are foreign to the human body and its function. Lack of the nutrient iodine is the main cause of what used to be commonly called “goiter”.
When it was determined that iodine deficiency was a common cause of goiter, iodine was added to our common table salt. This seems to have alleviated the problem. However, the recent recommendations to reduce salt intake may have contributed to a resurgence of hypothyroidism.
How does the health care professional determine that a patient has hypothyroidism?
Usually a simple blood test measuring the T4 (thyroid hormone) and TSH (thyroid stimulating hormone) are used to make a determination. If the T4 measures low and the TSH is elevated, it is assumed that the thyroid is not responding to the pituitary’s signal to produce more T4. If both are low, there is a possibility of a pituitary problem.)
There are many possible “symptoms” of hypothyroidism. The most common are lack of energy, moodiness, dry skin, hair loss (especially at the outer edges of the eyebrows), sexual dysfunction, and brain “fog”. Usually the commonly used blood tests can determine if there is a deficiency and the treatment is Levothyroxine (Synthroid, Levoxyl, Levothroid, Tirosint, and Unithroid.) Dosing for adults is typically 1.7 micrograms of levothyroxine per kilogram of body weight but may vary by patient. Usually a health care professional will continue the T4 and TSH blood testing until the correct dosage is reached.
There are some symptoms to watch for in the event that you are receiving too much thyroid hormone. Contact your health care professional if you experience chest pain, shortness of breath, leg cramps, headaches, irregular heartbeats, sleeplessness, excessive sweating, tremors, vomiting, diarrhea, fever, skin rash or heat intolerance. Thyroid medication is prescribed to be taken for life. Do not discontinue medication without talking to your health care professional. Always tell your dentist, doctor, or any other health care provider that you take medication for hypothyroidism.
Desiccated Thyroid Hormone
Brand names include Armour Thyroid and Nature Thyroid. These are made of dried porcine (pig) thyroid. Before the synthetic thyroid hormone (Synthroid, etc.) came into use in the 1970’s, desiccated thyroid was used to treat hypothyroidism. Among medical professionals it is generally thought that the synthetic hormone is superior because the animal hormone is more difficult to standardize. However, when synthetic thyroid hormone is not effective in some patients, desiccated thyroid may be used and some patients prefer this. Research on the benefits of both synthetic and natural thyroid hormone is ongoing.
How to keep a normal thyroid healthy
We know that iodine is essential to maintaining thyroid health. Iodine levels in the United States have dropped by about one-half since the 1970’s throughout the 1990s. Although it is rarely used, there is a fairly accurate urine test to determine iodine levels in the human body. The body does not make iodine and must depend on oral intake to maintain adequate levels. Iodine deficiency is a world-wide problem and the World Health Organization has made the elimination of the deficiency a major priority. The Japanese consume nearly 90 times more iodine than Americans. They have reduced rates of chronic diseases and the lowest cancer rates of any developed country. This appears to be due to the increase in iodine intake.
Too much iodine can cause problems also especially for those patients who have radiologic procedures where intravenous dye containing iodine is used. Some people who move from iodine deficient areas such as the US Midwest to an area where seafood and iodine are readily available can occasionally become hyperthyroid from consuming seafood when their thyroids are used to efficiently using the small amounts that were previously available. This is rare and deficiency is far more common.
Since iodine deficiency can be a cause of hypothyroidism, how can we get more in our diet especially if we live in an area that is not near a saltwater source where iodine is abundant?
Take a multivitamin containing iodine.
Increase our consumption of saltwater fish.
Eat seaweed in the form of kelp, dulce or nori) These are available at your local supermarket as seaweed snacks.
Consume Bladderwrack (a seaweed high in iodine) and often recommended by naturopaths and herbalists to supplement iodine.
Take a supplement containing kelp.
Consume more shellfish.
Previously mentioned was the danger of contaminants that damage the thyroid. The three main culprits are bromide, fluoride and chlorine.
Bromide is found in pesticides, brominated vegetable oil often added to citrus drinks, plastics, soft drinks, flame-retardants added to furniture, carpet and textiles. It is also found in toothpaste, hair products, and cosmetics.
The US has been slow to ban bromine additives as the UK, Canada and Brazil have done.
Ways to avoid Bromine:
Eat organic and wash all produce thoroughly.
Avoid eating or drinking from plastic containers.
Buy organic whole grain bread and flour.
Do not drink soda.
Use personal products that are as non –toxic as possible.
Maintain ventilation in cars and buildings. (Studied show indoor air is more contaminated than outdoor air.)
Do not consume un-fermented soy.
Ways to avoid fluoride:
Use fluoride free toothpaste.
Avoid fluoridated water.
Take calcium, magnesium and vitamin C which bind to the fluoride ions and help to flush them from the body.
Eat organic. Avoid pesticides.
Ways to avoid chlorine:
Do not drink chlorinated water.
Use a water filter in your shower to help remove chlorine and other contaminants.
Avoid chlorinated pools.
Do not use chlorine bleach for household cleaning.
Hyperthyroidism is a condition of the thyroid when it produces too much thyroid hormone. Symptoms include, sudden weight loss, rapid heartbeat (over 100 beats per minute), increased appetite, sweating, fatigue and muscle weakness, sensitivity to heat, more frequent bowel movements, thinning skin, brittle fine hair, enlarged thyroid (may appear as a swelling in the neck), nervousness, anxiety, and irritability, as well as menstrual changes.
What causes hyperthyroidism?
Graves Disease is an autoimmune disorder. It is the most common cause of hyperthyroidism. Anti-bodies typically function as protection against bacteria, viruses and other foreign substances that afflict the body. In Graves Disease these antibodies attack the thyroid by mistake. Occasionally the antibodies affect the tissue behind the eyes causing the eyeballs to bulge. Skin on the lower legs can also be affected. The exact cause is unknown but it appears there is a genetic predisposition.
Thyroiditis is a condition where the thyroid gland can become inflamed absent a specific cause. Due to the inflammation, excess thyroid hormone may be leaked into the bloodstream. There is a type of thyroiditis, sub-acute granulomatous (rare), that causes pain in the thyroid gland. Other types are typically painless.
Toxic adenoma, Plummer’s disease, and toxic multinodular goiter are all conditions that cause the thyroid to produce excess T4. Usually these conditions present as nodules on the thyroid or swelling in the area of the thyroid gland.
Treatment for Hyperthyroidism
Treatments vary depending on they type of hyperthyroidism, age of the patient and other concurrent medical conditions.
Tapazole (methimazole) is a drug that blocks the thyroid from producing new thyroid hormone. It is currently the drug of choice because it causes less severe side effects. They do not cause permanent damage to the thyroid and work fairly quickly to alleviate symptoms. In some Graves disease patients a treatment regimen of 12 to 18 months will result in a lengthened remission of the condition.
Side effects are rare but do occur in 5% of patients treated with this drug. Common reactions are joint pains, rashes, hives and fever. Rarely a serious side effect, agranulocytosis can manifest. This is a condition in which the white blood cells rapidly drop or completely disappear. In the event of a fever or sore throat, the drug should be discontinued and immediate medical intervention should be sought. Continuing to take the drug in this situation could cause a life threatening infection.
Treatments for hyperthyroidism
Radioactive iodine is used to destroy or damage the thyroid cells that produce the thyroid hormone. The radioactive iodine is administered in capsule form by mouth just one time. The thyroid (which has an affinity for iodine) quickly takes in the radioactive iodine and this causes the thyroid and/or the nodules. It typically takes several weeks or months for the thyroid to shrink in size and return the levels to normal. Some patients may require a second treatment with radioactive iodine. For more than 60 years radioactive iodine and has been found to be generally safe.
Surgical removal of the thyroid
A permanent cure for hyperthyroidism is surgical removal of the entire thyroid gland. Prior to the surgery patients are usually treated with SSKI or supersaturated potassium iodide or with Lugol’s iodine solution. This reduces the blood supply to the thyroid making the surgical procedure safer. Incidence of surgical complications are less than 1%. After thyroid removal patients become hypothyroid requiring a daily supplement of thyroid hormone replacement.
Beta-blockers may be prescribed to treat hyperthyroidism because they block the action of thyroid hormone in the body. Even though they do not change the thyroid hormone levels, they may be used to alleviate symptoms. Until another form of treatment has time to take effect. An example would be after the radioactive iodine treatment until the treatment has a chance to take full effect.
The thyroid is part of a complicated system that maintains a balance of the metabolism in the human body. We have presented some basic information here. For more details, go to www.thyroid.org or www.endocrineweb.com. And as always check with your healthcare provider if you have questions.