Doctors prescribe the thyroid hormone treatment levothyroxine (Euthyrox, Levoxyl, Synthroid, Tirosint, Unithroid) more frequently than most other drugs in the pharmacy. Although levothyroxine alone is the standard treatment for people with underactive thyroid glands, not everyone taking this medication feels well. Could combination therapy work better than this single hormone?
Will Combination Therapy Work Better Than Synthroid?
Q. My thyroid gland was removed three years ago. I have never felt right on Synthroid. I’ve also tried a combination of Synthroid and Cytomel and recently Armour Thyroid.
Of all three, I’ve found Armour Thyroid is the best. I split it and take multiple doses throughout the day to avoid heart palpitations.
Most endocrinologists as well as primary care physicians adjust the thyroid dose based on the TSH test. That will be low when you take T3 (which is a natural part of Armour Thyroid). I’ve been informed that the blood test should be done in the early AM and food and thyroid meds shouldn’t be taken for 12 hours before blood is drawn for labs.
People Who Don’t Do Well on Levothyroxine Alone:
A. We consulted one of the world’s foremost authorities on thyroid function, Dr. Antonio Bianco, professor of medicine at the University of Chicago School of Medicine. He has found that up to 15 percent of patients don’t feel good on levothyroxine alone (Thyroid, June 2018). This may be due at least in part to genetic differences in the enzymes that convert T4 (levothyroxine) to the active T3 hormone (triiodothyronine) (Frontiers in Endocrinology, July 9, 2019).
Dr. Bianco points to evidence that a normal TSH (thyroid stimulating hormone) does not necessarily indicate optimal thyroid hormone activity throughout the body. Although most endocrinologists still use TSH as the gold standard and prescribe levothyroxine alone as treatment, Dr. Bianco suggests that treatment should be personalized. He and his colleagues look forward to prescribing a combination therapy that will be individualized and provide the hormones patients need. Armour and other desiccated thyroid extracts made from pig thyroid glands fall short. That’s because the ratio of T3 to T4 is different in pigs and humans.
As for the blood test, your advice is good. TSH levels are significantly lower after the morning meal (Indian Journal of Endocrinology and Metabolism, May-June 2017) than before it. Levels of free T4 do not appear to be affected by the time of day or whether the patient is fasting.
Who Will Benefit from Combination Therapy for Hypothyroidism?
The goal is for patients to feel good. For some patients, this will mean using combination therapy or desiccated thyroid extract such as Armour. Others do well on levothyroxine but may need to adjust when they take their medication. Synthroid, Levoxyl and probably generic levothyroxine may not be absorbed as well if taken at the same time as iron or calcium supplements. Even coffee can reduce absorption, so some people find that taking their thyroid hormone at bedtime works well.
People who would like to learn more about treating thyroid problems with combination therapy may wish to read our eGuide to Thyroid Hormones. You might also wish to listen to our interview with Dr. Bianco, which you can find here.