Hypothyroidism - Treatment

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Combination products containing T4 and T3, such as liotrix (Thyrolar), are available, but there is some controversy concerning their benefits. Several 2005 studies suggested that although some patients may prefer combination therapy, T3 and T4 together do not work better than T4 alone. Patients might like the combined drugs because they cause more weight loss, or a placebo effect may be involved. It does not appear that combination products offer any advantage for normalizing TSH levels.

Levothyroxine Regimens

Levothyroxine only needs to be taken once a day. It is slowly assimilated by body organs, so it usually takes up to 6 weeks before symptoms improve in adults. Nevertheless, many patients feel better after 2 to 3 weeks of treatment. The speed at which specific symptoms improve vary:

• Weight loss, less puffiness, and improved pulse usually occur early in the treatment.
• Improvements in anemia and skin, hair, and voice tone may take a few months.
• High LDL ("bad cholesterol") levels decline very gradually. HDL ("good cholesterol") levels are not affected by treatment.
• Goiter size declines very slowly, and some patients may require high-dose thyroid hormone (called suppressive thyroid therapy) for a short period.

Levothyroxine reduces blood pressure in about half of hypothyroid patients with hypertension, although blood pressure medications may still be needed.

Appropriate Dosage Levels. Initial dosage levels are determined on an individual basis and can very wide depending on a person's age, medication condition, other drugs they are taking, and, in women, whether they are pregnant or not. For example, pregnant women with hypothyroidism may require higher than normal doses.

• Starting out. Most individuals need to build up gradually until they reach a maintenance dose. In uncomplicated cases, the dose typically starts at 50 micrograms per day, which then increases in 3- to 4-week intervals until thyroid hormone levels are normal. Seniors and those with heart disease may start at 12.5 to 25 micrograms per day. On the other hand, young adults with a short history of hypothyroidism might be able to tolerate a full maintenance dosage right away.
• Maintenance dose. Maintenance dose for most patients averages 112 micrograms but it can vary between 75 and 260 micrograms. If conditions such as pregnancy, surgery, or other drugs alter hormone levels, the patient's thyroid needs will have to be reassessed.