Author: Yvette C. Terrie, BSPharm, RPh
Hypothyroidism is caused by a variety of factors, and adults, particularity women, should have a blood test to determine thyroid problems every 5 years to detect the condition and treat it effectively.
Hypothyroidism is an endocrine condition characterized by having an underactive thyroid gland, which results in a deficiency in the thyroid hormone. The thyroid gland is a butterflyshaped gland located in the front of the neck just below the voice box (larynx) and it releases the hormones that regulate the body’s energy and control metabolism. When levels of thyroid hormone are low, the body burns energy slower than normal and the heart rate and regulation of body temperature decrease as well.
Statistics show that an estimated 1% of all adults in the United States have some degree of hypothyroidism and that this condition affects an estimated 10% of patients in the elderly population.1
According to the American Association of Clinical Endocrinologists, an estimated 25 million people have some form of hypothyroidism, but only half have been diagnosed.2
While hypothyroidism can affect anyone at any age, it is most prevalent among females and affects an estimated 10% of women and 6% of men.
The disease is also more common among individuals older than 60 years. The American Thyroid Association recommends that adults, particularly women, have a blood test to detect thyroid problems every 5 years starting at age 35.3
While rare, hypothyroidism can also be caused by too much or too little intake of dietary iodine or by abnormalities of the pituitary gland. Certain factors may increase your chance of developing thyroid disorders. You may require more regular testing if you have2,3
• A previous thyroid problem, such as goiter or thyroid surgery
• A family history of thyroid disease
• Other autoimmune diseases including Sjögren’s syndrome, pernicious anemia, type 1 diabetes, rheumatoid arthritis, or lupus
• Turner syndrome, a genetic disorder that affects girls and women who are older than 60 years
• Been pregnant or delivered a baby within the past 6 months
• Received radiation to the thyroid or to the neck or chest.
Signs and Symptoms Asociated with Hypothyroidism
Hypothyroidism rarely causes symptoms in the early stages, but if left untreated over time it can cause a number of medical problems such as infertility, obesity, heart problems, and joint pain.
The symptoms associated with hypothyroidism can vary from patient to patient. The most common symptoms associated with hypothyroidism include:
• Fatigue, lack of energy
• Unintentional weight gain
• Puffy face
• Cold intolerance
• Joint stiffness and muscle pain
• dry skin
• dry, brittle, and thinning hair or fingernails
• hair loss
• Decreased sweating
• heavy or irregular menstrual periods
• Infertility issues
• decreased heart rate
• elevated cholesterol levels
If left untreated, patients may experience1,4
• decreased taste and smell
• puffy face, hands, and feet
• slow speech
• thickening of the skin
• thinning of eyebrows
Myxedema coma is referred to as the most severe form of hypothyroidism, and rarely occurs.1,3,4
It may be caused by an infection, illness, exposure to cold, or certain medications in individuals with untreated hypothyroidism. The symptoms and signs associated with myxedema coma include below normal temperature, shallow breathing, low blood pressure, and blood glucose, as well as unresponsiveness. 1,3,4
Diagnosis of Hypothyroidism
If your doctor suspects that you have hypothyroidism, he or she will obtain a blood sample and test your levels of thyroid hormone.
If you have been diagnosed with hypothyroidism your doctor will prescribe a synthetic form of the thyroid hormone. Levothyroxine, a synthetic thyroid hormone product, is the standard treatment for managing hypothyroidism and is available under various brand names (eg, Levothroid, Synthroid). The good news is that hypothyroidism can almost always be completely controlled with the use of synthetic levothyroxine, as long as the recommended dose is taken daily as instructed.
The exact dose will depend on your age and weight, the severity of the hypothyroidism, the presence of other health problems, and whether you are taking other drugs that might interfere with how well the body uses the thyroid hormone.
About 1 to 2 weeks after you start treatment with levothyroxine, you will likely notice that your levels of fatigue have improved. It is important that you take your medication exactly as prescribed and not miss any doses as well as maintain routine checkups with your primary health care provider.
Your doctor will monitor your thyroid stimulating hormone (TSH) levels about 6 to 8 weeks after you begin therapy and make any necessary dosage adjustments when warranted. If your dose needs to be adjusted, you will require more labs to check your TSH levels. Once you are at a stable dose, your doctor will typically require you to have blood tests repeated in 6 months, and then once a year after that.
While hypothyroidism cannot be prevented, you can lead a normal and productive life if you take your medicine as prescribed. Some important things to remember once you start taking thyroid hormone medication include3,4
• Take your medication exactly as directed by your doctor daily and at the same time every day.
• Since absorption of this medication is increased on an empty stomach, take your thyroid medicine on an empty stomach 30 minutes to an hour before breakfast.
• Do not stop taking the medication even if you feel better.
• Do not take your thyroid medication at the same time as fiber supplements, calcium, iron, multivitamins, or aluminum hydroxide antacids or any medications that bind bile acids. Take your thyroid medication and these medications at least 4 hours apart.
• After you start taking replacement therapy, if you have any adverse effects or concerns, you should immediately report them to your primary health care provider. Excessive amounts of thyroid hormone can cause various adverse effects which include palpitations, rapid weight loss, restlessness or shakiness, sweating, and insomnia.4
This handout for patients is available online at www.PharmacyTimes.com.
1. Hypothyroidism. Patient Education Center Web site. http://www.patientedu.org/aspx/HealthELibrary/HealthETopic.aspx?cid=197423. Accessed November 10, 2010.
2. What is Hypothyroidism? Abbott Laboratories Web site. http://www.synthroid.com/Hypothyroidism/Default.aspx. Accessed November 10, 2010.
3. Hypothyroidism. Medline Plus Web site. http://www.endocrine.niddk.nih.gov/pubs/Hypothyroidism/#cause. Accessed November 10, 2010.
4. Hypothyroidism. Mayo Clinic Web site. http://www.mayoclinic.com/health/hypothyroidism/DS00353/DSECTION=treatments-and-drugs. Accessed November 10, 2010.
Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.