I've read the entirety of Dr Toft's interview with Pulse magazine, and have found what seem to be inconsistencies in his position (denoted by ***). Can anybody explain?
6 What is the correct dose of thyroxine and is there any rationale for adding in tri-iodothyronine?
The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range – 0.2-0.5mU/l.
In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance.
But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.
***This ‘exogenous subclinical hyperthyroidism’ is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l).***
Even while taking the slightly higher dose of levothyroxine a handful of patients continue to complain that a sense of wellbeing has not been restored. A trial of levothyroxine and tri-iodothyronine is not unreasonable. The dose of levothyroxine should be reduced by 50µg daily and tri iodothyronine in a dose of 10µg (half a tablet) daily added.
***While taking both hormones it is important serum TSH is normal and not suppressed. If the patient is still dissatisfied it should be made clear that the symptoms have nothing to do with thyroid disease or its treatment and perhaps issues at home and in the workplace should be addressed.***
There is no place for the use of animal thyroid extract in the treatment of hypothyroidism. Although preparations contain both thyroxine and tri-iodothyronine, the hormone content varies between batches.5
And how does one apply formatting to posts? The usual html markers don't seem to work...