The Thyroid Foundation of America has become aware that the Food and Drug Administration has determined that different brands of thyroid hormone tablets are similar enough to make changes between brands or from brand to generic tablets appropriate. We do not agree.
Physicians evaluate the effectiveness of thyroid hormone treatment by measuring the serum TSH test. TSH stands for Thyroid Stimulating Hormone which is made in your pituitary gland and reflects the amount of active thyroid hormone in your system. If your thyroid hormone levels are too low, TSH will be high. If you have too much thyroid hormone, your TSH will be low or absent. Even slight changes in TSH level could signify a serious health risk. The problem is that most patients and many physicians may not be aware that a change in thyroid prescription may change the TSH and pose serious health risks.
If the thyroid hormone level rises above normal as a result of a medication change elderly individuals have an increased risk for osteoporosis and for heart rhythm problems, including atrial fibrillation which can cause heart attacks, strokes, or heart failure. Anyone with underlying heart disease could be at markedly increased risk for these complications. Patients with thyroid cancer are often given thyroid treatment to raise thyroid hormone levels above normal to suppress cancer cell growth. They too could have heart problems if new treatments further elevated their thyroid hormone levels.
Should the thyroid level fall as a result of a change in thyroid hormone medication, pregnant women who have been appropriately regulated on their previous medication could be at risk for hypothyroidism. Even mild degrees of hypothyroidism have been shown to increase a pregnant women’s risk for miscarriage, a low birth weight baby, hypertension at the time of delivery, and a possible IQ deficit in their baby.
TFA recommends that you stay on whatever brand of thyroid hormone that your doctor prescribes. If your doctor does recommend a different thyroid medication for you, TFA recommends that you discuss with your doctor having a repeat TSH test in 4 to 6 weeks. If your TSH level is no longer normal, your doctor will advise you about an appropriate adjustment of your thyroid hormone dosage based on the results of your new TSH test. Six weeks after this adjustment, a final TSH test should be done to ensure stability and appropriate hormone levels. We note that it is likely that there will be a cost for such a change because of the need for extra office visits and extra TSH tests which may or may not be covered by your health insurance. We urge you to discuss these issues with your physician.
In some states, a pharmacist may make the recommendation for a change to a different brand or generic thyroid hormone. If so, discuss the changes with your physician who is better informed about your overall medical health and in the best position to make that decision.
We would also appreciate it if you would answer our TFA Thyroid Treatment Questionnaire giving us your experiences if you do change your medication.
If you have questions about this or other thyroid issues, please contact us by phone at 800-832-832.