Injudicious use of thyroid hormone

A few years ago I wrote an editorial expressing my concerns about the diagnoses of Wilson’s syndrome and adrenal fa­tigue, both of which naturopaths consider common disorders (TDF: Trendy diag­nosis fatigue, BCMJ 2007;49:471). At that time I was not familiar with the complete treatment protocol for Wilson’s syndrome. 

Since that time there have been reports of patients who have developed overt hyperthyroidism and cardiac dysrhythmias, particularly atrial fibrillation while on this treatment, and I thought it important that the potential risks of this treatment be brought forward.

On reviewing the details of this treatment, I found that the use of “supraphysiologic cyclic dosing” of slow release T3 (liothyronine) is used to “reset low body temperature and re­calibrate metabolic rate” (really?). Body temperature alone is used to determine dose and treatment cycle length. In brief, the protocol involves starting T3 at 7.5 µg every 12 hours and increasing by 7.5 µg daily until temperature reaches 37 °C.

Sometimes doses up to 90–105 µg twice daily are needed to achieve this. If the target temperature is not reached once these high doses are used, the dose is tapered by 7.5 µg every 2 days down to nothing, then the cycle restarted. The cycles are repeated until target temperature is reached. In many patients it may take months and in some it is never achieved. If it is reached then that dose is maintained for a few weeks, then tapered off, to begin again if symptoms recur.

A large proportion of patients are very likely to be hyperthyroid for significant periods of time during this treatment. In fact, one article describing the treatment stated that a significant number of patients suffer from symptoms of increased heart rate, irritability, and shakiness. Is this surprising? Sounds suspiciously like hyperthyroidism to me. 

No mention was made of thyroid levels being measured when those symptoms occurred. If one were to treat hypothyroidism with T3 alone (which is not common practice, at least among endocrinologists), most individuals would not require more than 75 mcg daily. Fortunately, atrial fibrillation occurring in this setting resolves once the thyroid levels normalize (off T3).

Atrial fibrillation is a common dysrhythmia, and in the investigation of possible reversible causes of it, thyroid levels are routinely measured to rule out hyperthyroidism. Iatrogenic hyperthyroidism, from what is in my view inappropriate and injudicious use of thyroid hormone, is harmful and potentially dangerous. 
—SEH