Using T3 for Symptoms of Hypothyroidism

Hypothyroid Patients May Feel Better with a Combination of T4 and T3

Oct 9, 2009 Melissa Murfin

Some patients with hypothyroidism still have symptoms on levothyroxine alone. Adding T3 to their treatment may be helpful.

According to the American Thyroid Association, approximately 2 to 3% of Americans have hypothyroidism. This common disorder is easily treated in many patients with a synthetic thyroid hormone replacement known as levothyroxine (Synthroid, Levoxyl, others). Unfortunately, some people with underactive thyroid still notice symptoms despite apparently normal thyroid lab results.

The T4 and T3 Connection

In humans, thyroxine (T4) is produced mainly by the thyroid. It is converted in the tissues to triiodothyronine (T3), which is a more active, more potent form of thyroid hormone. There are thyroid receptors on nearly every cell in the body which is why hypothyroidism produces such a wide variety of symptoms.

When to Use T3

Most hypothyroid patients do well with symptom management on levothyroxine alone. Others may still notice symptoms such as:

• fatigue
• hair loss
• depression
• weight gain

Because these symptoms are not specific to hypothyroidism, they may come from other causes such as anemia, sleep apnea or stress. Anyone experiencing these symptoms should have a thorough evaluation with their healthcare provider. When other causes are ruled out, the addition of synthetic T3 in the form of liothyronine (Cytomel) may help.

Adding T3 to Levothyroxine

T3 is not usually given alone, but added when a patient is already on levothyroxine. Depending on their lab results, T3 may be directly added to the levothyroxine. This is often done when the TSH is above the goal range. If the TSH is within goal, the levothyroxine dose is reduced to accomodate the additional T3.

Conversion of Levothyroxine Monotherapy to T4/T3 Combination Treatment

T3 is approximately 4 times more potent than T4. An equivalent dose of liothyronine is one-quarter the dose of levothyroxine. For example, for a patient currently taking levothyroxine 100 mcg daily with normal thyroid labs, the dose may be decreased to 75 mcg daily. Liothyronine can then be added as a 5 mcg dose. A 5 mcg dose of liothyronine is roughly equal to 20 mcg of levothyroxine, making the total levothyroxine dose equivalent 95 mcg. This is very close to the patient's original dose of 100 mcg daily.

Dose of Cytomel

Generic liothyronine and brand Cytomel only come in two dose strengths: 5 mcg and 25 mcg. Most patients are started on 5 mcg of liothyronine daily. If the patient tolerates the dose, it may be increased to 5 mcg twice daily. The first dose can be taken with the levothyroxine dose in the morning. The second dose should be taken around 2 to 3 pm. This is done to because liothyronine only lasts in the body approximately six to eight hours.

Side Effects of T3

T3 can be very stimulating, similar to caffeine. Sensitive patients may have palpitations, racing heart or an irregular rhythm. They can have difficulty sleeping, particularly if the afternoon dose is taken too late. Some patients also notice anxiety or tremor with liothyronine.

Too much T3 can be dangerous. Excess thyroid hormone can cause a heart rhythm known as atrial fibrillation. This can lead to a stroke. Long-term, too much thyroid hormone can cause bone loss leading to osteoporosis. Some patients may take extra thyroid hormone because they feel more energy. This stimulating effect is similar to someone who takes speed or amphetamines and can be detrimental to the patient's heart and bones.

Who Should Avoid T3?

Patients with existing heart problems may be too sensitive to the stimulating effects of T3. A patient with a history of afib or heart attack should avoid T3. Treatment with T3 should considered carefully in elderly patients, due to the cardiac risks. Relatively healthy elderly hypothyroid patients can use T3, but should be started at 2.5 mcg daily with the dose increased slowly.

Osteoporosis patients can use T3 as long as it is not given in excess doses. Too much thyroid hormone can worsen bone loss, increasing fracture risk.

What to Do for Unrelieved Symptoms of Hypothyroidism

Hypothyroid patients with symptoms should see their healthcare provider to discuss the possibility of using T3. Thyroid symptoms are very nonspecific which means many other causes could be contributing to fatigue, depression, and hair loss. Patients will need a thorough evaluation to rule out other factors that could be causing problems. Unfortunately, T3 is not a cure-all, but is worth a try for the right patients.

Sources

American Thyroid Association

The copyright of the article Using T3 for Symptoms of Hypothyroidism in General Medicine is owned by Melissa Murfin. Permission to republish Using T3 for Symptoms of Hypothyroidism in print or online must be granted by the author in writing.

Thyroid and Parathyroid

Thyroid Medication

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Comments

Oct 20, 2009 10:51 AM

Guest :

We have to take Cytomel only with Liothyroxin or can we take along with Eltroxin also?

Nov 4, 2009 4:39 PM

Guest :

I have taken Cytomel for about 10 years (along with Eltroxin) it
has helped me tremendously. I did not know it will last only
up to about 6 hours,so I will try taking my second dose in the
afternoon, I was told take 1/2 in the morning the other half at
dinner. I have an underactive thyroid because I was given radiation
treatment at 13 months old, (a treatmet to prevent cribdeath) thymus
gland was radiated which is right next to the thyroid, at 40 I had
a large benign tumour on my thyroid, it shrunk with medication, but still had symptons,I found a great Endocronoligist that put me on cytomel and felt so much better!

2 Comments