Which medication is best for treating a low-functioning thyroid?
A low-functioning thyroid is one of the most common medical conditions diagnosed by physicians.
Supplementation with thyroid hormone has been the gold standard for treatment for over 100 years.
The most common medication prescribed for hypothyroidism is the many brands of T4 (tyrosine with four iodine molecules attached) with Synthroid being the most common name brand.
In the past, dried pig thyroid, containing T4 and T3 (tyrosine with three iodine molecules attached) was used as a medication for hypothyroidism. An early medication of this kind is still around today, Armour thyroid.
Today there is some controversy about which medication should be used to treat hypothyroidism. Many physicians feel that T4 is the only option while other physicians are open to the use of a T4/T3 combination in select patients.
Hypothyroidism is common. Almost 20 million Americans have some form of thyroid disease with the majority being hypothyroid. Women are affected more than men and hypothyroidism increases with age.
Hypothyroidism may be even more common since it has been estimated that 60 percent of people with thyroid disease do not know that they have thyroid disease.
Hypothyroidism increases the risk of heart disease, osteoporosis and infertility. The more common symptoms of hypothyroidism include fatigue, constipation, sensitivity to cold, weight gain, dry skin, hair loss and loss of memory.
The most common test for thyroid function is the thyroid stimulating hormone (TSH) made in the pituitary gland of the brain. Although this is commonly accepted as the gold standard measurement for thyroid function, many illnesses and medications can affect the TSH level even if the thyroid is functioning correctly.
Measurement of other thyroid hormones like T3 and T4 along with TSH give a better picture of the state of the thyroid gland.
Although the vast majority of people who are hypothyroid do very well with a T4 medication, medical research has demonstrated that about 5 to 10 percent of hypothyroid people do not respond well to T4. According to several medical studies, they respond very well to a combination of T4/T3 made from desiccated pig thyroid.
A recent medical study also demonstrated that hypothyroid patients did equally as well on a combination T3/T4 medication when compared to a T4 medication. However, most physicians do not feel comfortable in prescribing T3/T4 combination medication and a significant number of hypothyroid people suffer needlessly.
One of the reasons why physicians are less than enthusiastic about desiccated pig thyroid is that 40 years ago one study demonstrated that the amount of T3 and T4 varied from batch to batch. Since then the pharmaceutical companies that make T3/T4 combination medications have made substantial quality improvements.
In my medical practice I have patients who do well on T4 medications as well as T3/T4 combination medications.
A T3/T4 combination medication might not be right for everyone, but in my experience, patients with symptoms of hypothyroidism while on the right dose of a T4 medication often have resolution of their symptoms with a T3/T4 combination medication.
• Patrick B. Massey, MD, PH.D., is medical director for complementary and alternative medicine at Alexian Brothers Hospital Network and president of ALT-MED Medical and Physical Therapy, 1544 Nerge Road, Elk Grove Village. His website is www.alt-med.org.